Christian ethics

Branch of theology that defines virtuous and sinful behavior from a Christian perspective

Christian ethics, also called Moral theology, was a branch of theology for most of its history. It separated from theology during the Enlightenment of the eighteenth and nineteenth centuries, and for most scholars of the twenty-first century, it holds a niche between theology on one side and the social sciences on the other. The Christian ethical system is both a virtue ethic, which focuses on the building of an ethical character and what kind of person we ought to be, and a deontological ethic, which assesses choices and what we ought to do.

Christian ethics originated during the period of Early Christianity between AD27-30 and AD325. It continued to develop throughout the middle ages when the rediscovery of Aristotle led to scholasticism and the writings of Thomas Aquinas. The Reformation, Counter-Reformation and Christian humanism all had a lasting impact on Christian ethics particularly its political and economic teachings. Modern Christian ethics has been heavily impacted by the loss of its connection to theology and by secularism.

Christian ethics takes its metaphysical core from the Bible, seeing God as the ultimate source of all power. Evidential, Reformed and volitional epistemology are the three most common forms of Christian epistemology. Since the Bible is the foundation of Christian ethics, and the Bible has a variety of ethical perspectives, there has been disagreement over the basic ethical principles of Christian ethics from its beginnings with seven of them requiring perennial reinterpretation. Christian ethicists use reason, natural law, the social sciences and the Bible to argue modern interpretations. The Christian ethical system is applied to every area of life, and its principles are used to make decisions concerning politics, relationships, bioethics, environmental ethics and more.

Christian ethics, also called Moral theology, was a branch of theology for most of its history.[2]:15 As a field of study, it was separated from theology during the Enlightenment of the eighteenth and nineteenth centuries, and for most scholars of the twenty-first century, it has become a "discipline of reflection and analysis that lies between theology on one side and the social sciences on the other".[3]:41[4] The Christian ethical system is both a virtue ethic, which focuses on the building of an ethical character, and it is also a deontological ethic which assesses choices as morally required, forbidden, or permitted. These two approaches are normally seen as contrasting with one another,[5] yet within the Christian ethical system, they are combined.[6][7]

Theologian Joseph Sittler is quoted as saying the Christian ethic can be defined as "faith doing".[8]:7 According to theologian Servais Pinckaers, "everyone admits [that] Christians ethics is the branch of theology that studies human acts so as to direct them to a loving vision of God seen as our true, complete happiness and our final end. This vision is attained by means of grace, the virtues, and the gifts, in the light of revelation and reason".[9] Theologian Emil Brunner makes it a point to differentiate Christian ethics from the broader topic of philosophical ethics: the broad topic of ethics is about principles of right and wrong conduct, but Brunner says the Christian conception of 'good' differs because it cannot be defined by principles alone. That would be a kind of legalism that is contrary to Christian ethics.[10]:82 According to Brunner, the specific element in Christian ethics that sets it apart is the belief that good human conduct arises out of interaction with the grace of God.[10]:85 This includes morality that arises from natural law and human nature.[4]:11–12

According to Pinckaers, the sources of Christian ethics are the "Scriptures, the Holy Spirit, the Gospel law, and natural law".[11]:xxi, xiii In the Wesleyan tradition, the four sources are scripture, tradition, reason, and Christian experience.[12] Christian ethics takes from the Bible its patterns of moral reasoning that focus on conduct and character in what is sometimes referred to as virtue ethics.[13]:9;11 Christian ethics has also had a "sometimes intimate, sometimes uneasy" relationship with Greek and Roman philosophy taking some aspects of its basic principles from Plato, Aristotle and other earlier philosophers.[14]:16

Christian ethics began its development during the period of Early Christianity which is generally thought to have begun with the ministry of Jesus (c. 27-30) and ended with the First Council of Nicaea (325).[15][16]:51 It emerged out of the heritage shared by both Judaism and Christianity, and depended upon the Hebrew canon as well as important legacies from Greek and Hellenistic philosophy.[14]:1,16 The Council of Jerusalem, as reported in Acts 15, may have been held in Jerusalem about 50AD. Its decree, known as the Apostolic Decree, to abstain from blood, sexual immorality, meat sacrificed to idols, and the meat of strangled animals, was held as generally binding for several centuries and is still observed today by the Greek Orthodox church.[17] Early Christian writings give evidence of the hostile social setting in the Roman empire as Christian ethics sought "moral instruction on specific problems and practices".[14]:2,24 These were not sophisticated ethical analyses, but were instead the practical application of the teachings and example of Jesus to confront specific issues.[14]:24 After Christianity became legal in the fourth century, the range and sophistication of Christian ethics expanded. Through such figures as Augustine of Hippo, Christian ethical teachings had a defining influence upon Christian thought that lasted for several centuries.[15]:774 For example, Augustine's ethic regarding the Jews meant that, "with the marked exception of Visigothic Spain in the seventh century, Jews in Latin Christendom lived relatively peacefully with their Christian neighbors through most of the Middle Ages" until around the 1200s.[18]:xii[19]:3

In the centuries following the fall of the Roman empire, practices of penance and repentance, using books known as penitentials were carried by monks on their missionary journeys thereby spreading the ethic.[16]:52–56,57 In the middle ages there are "7 capital sins... 7 works of mercy, 7 sacraments, 7 principle virtues, 7 gifts of the Spirit, 8 beatitudes, 10 commandments, 12 articles of faith and 12 fruits of faith".[20]:287 The medieval and renaissance periods saw a number of models of sin listing the seven deadly sins and the virtues opposed to each. The crusades were products of the renewed spirituality of the central Middle Ages when the ethic of living the Apostolic life and chivalry began to form.[21]:177[22]:130–132

Inaccurate Latin translations of classical writings were replaced in the twelfth century with more accurate ones. This led to an intellectual revolution called scholasticism, which was an effort to harmonize Aristotelian and Christian thought.[23]:220,221 In response, Thomas Aquinas (1225–1274) wrote "one of the outstanding achievements of the High Middle Ages", the Summa Theologica, that became known as Thomism, containing many ethics that continue to be used.[23]:222

By the 1200s, both civil and canon law had become such a major aspect of ecclesiastical culture that law began dominating Christian ethics.[24]:382 Most bishops and Popes were trained lawyers rather than theologians.[24]:382 The legal regulations of the church, and "divine moral law", became confounded, and the moral principle was "lowered to the level of jural legislation".[20]:286 "This mixing of the ethical and the juridicial was communicated to the whole thinking of the age".[20]:292

Luther, in his classic treatise On Christian Liberty argued that moral effort is a response to grace: humans are not made good by the things they do, but if they are made good by God's love, they will be impelled to do good things.[14]:111 John Calvin adopted and systematized Luther's main ideas grounding everything in the sovereignty of God.[14]:120 In Calvin's view, all humans have a vocation, a calling, and the guiding measure of its value is simply whether it impedes or furthers God's will. This gives a 'sacredness' to the most mundane and ordinary of actions leading to the development of the Protestant work ethic.[14]:116–122 Calvin upheld the separation of the spiritual and earthly roles for government, asserting that one important role of civil government is to provide restraint for evildoers.[14]:122,123 Thus, Calvin also supported just war in opposition to the pacifism of the Anabaptists of his time.[14]:124 The Reform ethic contributed to ideas of popular sovereignty asserting human beings are not "subjects of the state but are members of the state".[14]:125 During the Reformation, Protestant Christians pioneered the ethics of religious toleration and religious freedom.[25]:3

Max Weber asserted that there is a correlation between the ethics of the Reformers and the predominantly Protestant countries where modern capitalism and modern democracy developed first.[14]:124[26] The secular ideologies of the Enlightenment followed shortly on the heels of the Reformation, but "it is a nice question whether those (Enlightenment) ideas would have been as successful in the absence of the Reformation, or even whether they would have taken the same form".[14]:125

The Roman Catholic church of the 1600s responded to Reformation Protestantism in three ways.[23]:335 Papal reform began with Pope Paul III (1534 - 1549). New monastic orders grew with the most influential being the Society of Jesus commonly known as the Jesuits.[23]:336 The Jesuits commitment to education put them at the forefront of many colonial missions.[23]:336 The third response was by the Council of Trent in 1545 and 1563. The Council asserted that the Bible and church tradition were the foundations of church authority, not just the Bible as Protestants asserted; the Vulgate was the only official Bible and other versions were rejected; salvation was through faith and works, not faith alone; and the seven sacraments were reaffirmed. "The moral, doctrinal and disciplinary results of the Council of Trent laid the foundations for Roman Catholic policies and thought right up to the present".[23]:337

Christian humanism taught that any Christian with a "pure and humble heart could pray directly to God" without the intervention of a priest.[23]:338 They believed that imitating the early church would revitalize Christianity and restore its original purpose. "The outstanding figure among the northern humanists — and possibly the outstanding figure among all humanists — is the Dutch scholar Desiderius Erasmus".[23]:338 His ethical views included advocating for education in the humanities, "emphasizing the study of Classics, and honoring the dignity of the individual. He promoted the philosophy of Christ as expressed in the Sermon on the Mount and in living a humble and virtuous life".[23]:339

Christian ethics separated from theology in the Enlightenment era.[3]:41 The authority of the Bible, faith and religion itself were challenged by pietism and rationalism.[27]:465 This eventually led to the post-modern view that no appeal to authority can be accepted as sufficient to establish truth.[3]:ix The primary concern of the early modern period was the nature of human nature. This included discussion of where moral authority comes from and what defines human responsibility, free will, the nature of the self, and moral character. "Beginning with the rise of Christian social theory" in the nineteenth century, Christian ethics became heavily oriented toward discussion of nature and society, wealth, work, and human equality.[27]:511–512 In the nineteenth and twentieth centuries, "the appeal to inner experience, the renewed interest in human nature, and the influence of social conditions upon ethical reflection introduced new directions to Christian ethics".[27]:511–512

Multiple versions of modern Christian ethics have been produced by the influence of different strands of thought. There is also geographic diversity in modern Christian ethics.[27]:464 The Social gospel attempted to respond to the effects of modern industrialization.[3]:41 Immanuel Kant grounded morality in nature, independent of the authority of theology.[3]:41 Stanley Hauerwas asserts this separation of ethics and theology "impoverished" both fields.[3]:42 James M. Gustafson also asserts that modern ethics must be grounded in natural law while addressing both theology and ethics in "an integrative process" that is careful to consider circumstances, method, and procedures for decision making. At the same time, it must also "gather relevant information and knowledge from the social and natural sciences".[8]:xvi In the twenty-first century, Christian ethics is often on one side of a discussion and secularism on the other, with Christian ethics fighting for relevancy.[3]:2 William J. Meyer asserts the answer to this difficulty lies in embracing secular standards of rationality and coherence while refusing secular conclusions.[3]:5 The "struggle to embrace modernity without abandoning faith ... is arguably the critical fault line in the contemporary world".[3]:5

Gustafson sets out four basic points any theologically grounded ethic must address: (a) (metaphysics) God, his will, and his relation to the world and humans; (b) (epistemology) how humans know and distinguish justified belief from mere opinion, through human experience, community, nature and man's place in it; (c) (ethics) persons as moral agents; (d) and (applications) how persons ought to make moral choices and judge their own acts, the acts of others and the state of the world.[28]:14

The Christian metaphysic is rooted in the biblical metaphysic of God as 'Maker of Heaven and earth'.[4]:25 Philosopher Mark Smith explains that, in the Bible, a fundamental ontology is embodied in language about power, where the world and its beings derive their reality (their being, their power to exist, and to act) from the power of God (Being itself). Theology and philosophy professor Jaco Gericke says that metaphysics is found anywhere the Bible has something to say about "the nature of existence, reality, being, substance, mereology, time and space, causality, identity and change, objecthood and relations (e.g. subject and object), essence and accident, properties and functions, necessity and possibility (modality), order, mind and matter, freewill and determinism, and so on."[29]:207 According to Rolf Knierim, the Bible's metaphysic is "dynamistic ontology" which says reality is an ongoing dynamic process.[29]:208

In metaphysical language, the power of lesser beings participates in Power itself, which is identified as God.[30]:162 God as 'Maker of Heaven and earth' establishes that, within this system, whatever is, is good in its original created form. "The order of being is the order of value".[4]:25 Humanity is the highest level of development in creation, but humans are still creatures. In Christian ethics, the knowledge that human "creatureliness" is shared with all creation is not independent of knowledge of God.[10]:492 In the Christian metaphysic, humans have free will, but it is a relative and restricted freedom.[10]:494

The Christian view of the nature of reality has been called "biblical theism" and "biblical personalism": the belief that "ultimate reality is a personal God who acts, shows and speaks..."[13]:13,17 This view asserts that humans reflect the relational nature of God.[13]:13,17 Christian voluntarism points to the will as the core of the self. The Christian ethic says that within human nature, "the core of who we are is defined by what we love" and that this determines the direction of moral action.[4]:25–26

Within this ethical system, humans reflect the nature of ultimate reality, therefore they are seen as having a basic dignity and value and should be treated, as Kant said, as "an end in themselves" and not as a means to an end.[13]:18 Humans have a capacity for reason and free will which enable making rational choices. They have the natural capacity to distinguish right and wrong which is often called a conscience or natural law. When guided by reason, conscience and grace, humans develop virtues and laws. In Christian metaphysics, "Eternal Law is the transcendent blueprint of the whole order of the universe... Natural Law is the enactment of God's eternal law in the created world and discerned by human reason".[4]:11–12

Christian ethics asserts that it is possible for humans to know and recognize truth and moral good through the application of both reason and revelation.[4]:23 Observation, reasoned deduction and personal experiences, which includes grace and the experience of language, are the means of that knowledge.[31] "It is arguably one of Judaism's greatest contributions to the history of religions to assert that the divine Reality is communicated to mankind through words".[32]:129

Evidentialism in epistemology, which is advocated by Richard Swinburne (1934–), says a person must have some awareness of evidence for a belief for them to be justified in holding that belief.[33] People hold many beliefs that are difficult to evidentially justify, so some philosophers have adopted a form of reliabilism instead. In reliablilism, a person can be seen as justified in a belief, so long as the belief is produced by a reliable means even when they don't know all the evidence.[33]

Alvin Plantinga (1932–) and Nicholas Wolterstorff (1932–) advocate Reformed epistemology taken from Reformer John Calvin's (1509–1564) teaching that persons are created with a sense of God (sensus divinitatis). Even when this 'sense' is not apparent to the person because of sin, it can still prompt them to believe and live a life of faith. This means belief in God may be seen as a properly basic belief similar to other basic human beliefs such as the belief that other persons exist, and the world exists, just as we believe we exist ourselves. Such a basic belief is a 'warranted' belief even in the absence of evidence.[33]

Paul Moser has systematically argued for volitional epistemology. Moser contends that if the God of Christianity exists, this God would not be evident to persons who are simply curious. This God would only become evident in a process involving moral and spiritual transformation. This process might involve persons accepting Jesus Christ as a redeemer who calls persons to a radical life of loving compassion. "By willfully subjecting oneself to the commanding love of God, a person in this filial relationship with God, through Christ, may experience a change of character (from self-centeredness to serving others) in which the person’s character (or very being) may come to serve as evidence of the truths of faith".[33]

In Christian ethics, such "knowing" of God, truth and moral good is built on different assumptions than those of philosophical epistemology: James Gustafson says the Christian ethic assumes either a condition of piety, or at least a longing for piety.[8]:152 This piety is an attitude of respect evoked by "human experiences of dependence upon powers we do not create and cannot fully master".[8]:87 Such piety must be open to a wide variety of human experiences, including "data and theories about the powers that order life which come from many areas of human investigation".[8]:87 It engages the affections, and takes the form of a sense of gratitude.[8]:88 Trust is also seen as an aspect of knowing: underneath science is a trust that there is an identifiable order and discoverable principles beneath the disarray of complex data; this is comparable to the trust of the Christian faith that "there is unity, order, form and meaning in the cosmos ...of divine making".[4]:23–24 "Knowledge conditions are relative to particular communities" and all human knowledge is based on the experiences we have within the culture we live in: all human experience is interpretive.[28]:124

Every ethical system "presupposes some particular understanding of human nature, its capacities and its needs. Theocentrism is, therefore, an ethical stance as well as a metaphysical one".[28]:15–16 Christian ethics asserts the ontological nature of moral norms from God. Accordingly, it then asserts that the human is does not necessarily reflect the divine ought. The Christian ethic is also accountable to standards of rationality and coherence and must make its way through both what is ideal and what is possible.[4]:9 Thus, some biblical ethics are seen as "more authoritative than others. The spirit, not the letter, of biblical laws becomes normative".[4]:15

According to D. Stephen Long, the Hebrew Bible and the Life of Jesus in the New Testament provide the primary foundations of Christian ethics.[34][35] The diversity of the Bible means that it does not have a single ethical perspective but instead has a variety of perspectives; this has given rise to disagreements over defining the foundational principles of Christian ethics.[14]:2,3,15 For example, reason has been a foundation for Christian ethics alongside revelation from its beginnings, but Christian ethicists have not always agreed upon "the meaning of revelation, the nature of reason and the proper way to employ the two together."[14]:3,5 There are at least seven ethical principles that Christian ethicists have perennially reinterpreted.[14]:2

Christian ethics assumes the existence of good and evil, but has a particular frame of reference that begins from defining and understanding what is good.[36]:5 As everything begins with God, and God is defined as the ultimate good, the presence of evil and suffering must be adequately accounted for.[2]:219 Philosophy does not agree on a definition of evil, and there are at least two concepts of evil in use: a broad concept that defines evil as "any bad state of affairs, wrongful action, or character flaw" and includes all suffering, stemming from all natural events and moral actions, as evil.[37] The second is the narrow concept of evil. It only involves moral agents and their actions. Within the narrow view, nature is not a moral agent with the ability to choose, so natural evil has no moral quality.[33] The Christian ethic does not see all suffering as innately evil because the Christian story "is a story of the salvific value of suffering".[33]

There is tension between inclusivity and exclusivity inherent in all the Abrahamic traditions. According to the book of Genesis, Abraham is the recipient of the promise of God to become a great nation. The promise is given to him and his 'seed,' exclusively, yet the promise also includes that he will become a blessing to all nations, inclusively (Genesis 12:3).[38] Paul claims that because the 'seed' is singular, not plural, it refers to Christ, therefore baptized Gentile Christians are inclusively heirs of the promise if they have Abraham's faith even though they are not Jewish.[38] Yet by the second century, Christianity had also defined what it meant to be a Christian exclusively, by separating itself from Judaism and the Judaizers through its definitions of orthodoxy and heterodoxy.[39]:1 The God of the Bible is the inclusive God of all nations and all people, yet there is also "special membership" through baptism in the exclusive community identified with Him.[2]:628 Christians are referred to as the "elect" (Romans 8:33 Matthew 24:22) implying God has chosen some and not others for salvation, yet the Great Commission (Matthew 28:19) is a command to go to all nations. Christians and non-Christians have, throughout much of history, had significant moral and legal questions concerning this ethical tension.[40]:8 Yet there is no question that Christians pioneered the concept of religious freedom which rests upon an acceptance of the necessity and value of pluralism, a modern day concept often referred to as moral ecology.[25]:3[41]

Christian ethics emphasizes morality. The prophets of the Old Testament show God as rejecting all unrighteousness and injustice and commending those who live moral lives. The law and the commandments are set within the context of devotion to God. "God as lawgiver and judge has high moral expectations".[40]:8 This is sometimes offered as a contrast to the New Testament ethic, but this moral ethic is not a contrast; it's a pre-supposition. The Christian ethic is built on its Old Testament base.[40]:8,9 The Christian ethic requires not only the Old Testament rejection of active murder, but also the New Testament awareness of the anger and hatred that lead to it (Matthew 5:21-22).[40]:9 Yet, according to Martin Luther, the Christian ethic says those who follow the way of grace are no longer under law but are instead free from the law's power.[14]:111 In traditional Christian ethics, law and its just enforcement is overshadowed by the ethics of grace, mercy and forgiveness as aspects of redemption instead of punishment.[40]:9;116–120 "Part of the biblical legacy of Christian ethics is the necessity somehow to do justice to both sides".[40]:9 Human rights is the language through which the Christian ethic is able to relate these concepts to the world.[42]:310 In a convergence of opinion among Catholics, Lutherans, Reformed, and others, this has led to a support of human rights becoming common to all varieties of Christian ethics.[42]:304

Christian ethics asserts that "love is, and must remain", its foundation.[40]:331 Individuals are commanded to "turn the other cheek" Matthew 5:38-39, "love your enemies" Matthew 5:43-45, "bless those who persecute you" Romans 12:14-21 and more, as matters of personal conscience that define the very nature of being a Christian.[40]:330 Yet, "justice, as the institutional structure of love, is inevitably dependent upon other incentives, including, ultimately the use of force".[40]:331 The state's ability to create peace and order is in its ability to use force against those who create chaos, disorder and harm to others.[10]:469 Both the Old and the New Testaments contain explicit commands to respect authority.[40]:123 Christian ethics is, and always has been, divided over the interplay of justice, power and personal responsibility.[10]:469

According to the book of Genesis, God created and declared creation, including humans, good (Genesis 1:31). The Song of Songs depicts sensual love as good. Other parts of the Old Testament depict material prosperity as a reward. Yet, the New Testament references the life of the Spirit as the ultimate goal, and warns against worldliness.[40]:7 In the traditional view, this requires self-sacrifice, self-denial and self-discipline, and greatness lies in being a servant to all (Mark 10:42-45).[40]:7[4]:14 Yet according to ethicist Darlene Weaver, "there is no ontological split between self/other; there is no monolithic polarity of self-interested action versus other-regardingness. All people - each of us-in-relation-to-all - have a mandate rooted in God to the sort of self-assertion that grounds and confirms our dignity in relationship".[43]:62,64:64

There are a variety of Christian views on poverty and wealth. At one end of the spectrum is a view which casts wealth and materialism as an evil to be avoided and even combatted. At the other end is a view which casts prosperity and well-being as a blessing from God. The Christian ethic is not an opponent of poverty since Jesus embraced it, but it is an opponent of the destitution that results from social injustice.[44]:25 Kevin Hargaden says "No Christian ethic can offer a consistent defense of massive wealth inequality".[44]:77 Some Christians argue that a proper understanding of Christian teachings on wealth and poverty requires a larger view where the accumulation of wealth is not the central focus of one's life but rather a resource to foster the "good life".[45] Professor David W. Miller has constructed a three-part rubric which presents three prevalent attitudes among Protestants towards wealth: that wealth is (1) an offense to the Christian faith (2) an obstacle to faith and (3) the outcome of faith.[46]

Lisa Sowle Cahill calls sex and gender one of the most difficult topics in new studies of Christian ethics. As "the rigidity and stringency of [sic] traditional moral representation has collided head-on with historicized or "postmodern" interpretations of moral systems" tradition has acquired a new form of patriarchy, sexism, homophobia and hypocrisy.[47]:xi Feminist critics have suggested that part of what drives traditional sexual morality is the social control of women, yet within postmodern western societies the "attempt to reclaim moral autonomy through sexual freedom" has produced a loss of all sense of sexual boundaries.[47]:75;xi "Personal autonomy and mutual consent are almost the only criteria now commonly accepted in governing our sexual behavior".[47]:1 Christian ethics is, by its nature, a transformative ethic of discipleship.[47]:257;122 The gospel requires that all relationships be reconfigured by new life within the community, yet the New Testament has no systematic investigation into all facets of any moral topic, no definitive guidance for the many variations of moral problems that exist in the twenty-first century. [47]:121 Instead, New Testament authors challenge that which perpetuates sin, and encourage the transformation that embodies the reign of God.[47]:122

John Carman says the central question of Christian ethics is, and has always been, how the Christian and the church relates to the surrounding social and political world.[27]:463 "This has led to the development of three distinct types of modern Christian ethics: the church, sect and mystical types".[27]:463 In the church type (of Roman Catholicism and mainstream Protestantism), the Christian ethic is lived within the world, in marriage, family, and work, while living within and participating in municipal counties, cities and nations. This ethic is meant to permeate every area of life. The ethic of the sect works in the opposite direction. It is practiced by withdrawing from the non-Christian world, minimizing interaction with that world, while living outside or above the world in communities separated from other municipalities. The mystical type advocates an ethic that is purely an inward experience of personal piety and spirituality and often includes asceticism.[3]:465

Christian involvement in politics is both supported and opposed by the different types of Christian ethics.[48] Political science scholar Amy E. Black says Jesus' command to pay taxes (Matthew 22:21), was not simply an endorsement of government, but was also a refusal to participate in the fierce political debate of his day over the Poll tax. Gordon Wenham says: Jesus' response "implied loyalty to a pagan government was not incompatible with loyalty to God."[49]:7

The Christian ethic addresses warfare from the differing viewpoints of pacifism, non-resistance, just war, and preventive war which is sometimes called crusade.[50]:13–37[51] Where pacifism and non-resistance can be seen as ideals in action, just wars, preventive wars and crusades are actions in support of an ideal.[52]:155;161–165 In all four views, the Christian ethic presumes war is immoral and must not be waged or supported by Christians until certain conditions have been met that enable the setting aside of that presumption.[14]:336

Pacifism and non-resistance are opposed to all forms of physical violence based on belief that the example of Christ demonstrates it is better to suffer personally than to do harm to others. Non-resistance allows for non-combatant service where pacifism does not.[53]:63 They both presuppose the supersession of the New Testament over the Old, and believe in the separation of church and state to the degree the Christian does not owe obedience and loyalty to the state if that loyalty violates personal conscience.[53]:81–83;97 Both pacifism and non-resistance are interpreted as applying to individual believers, not corporate bodies, or "unregenerate worldly governments."[53]:36 Pacifism and non-resistance act as a conscience to society and as an active force for reconciliation and peace.[53]:63

Preventive war, crusade and just war recognize that harm can result from failing to resist a tyrannical enemy such as Hitler.[52]:154–155 Preventive war is waged in anticipation of an act of aggression that would violate our ideals of human rights, decency, and ordinary right and wrong.[52]:155;161–165 Crusade can be seen as an attempt to set right a past act of aggression that was not responded to at the time it occurred. "It attempts to undo what no one had the right to do in the first place".[52]:158 Just war says war can only be justified as self-defense or the defense of others. Its provisos are more from the Old Testament than the New.[54]:115–135[55]:270–274 The last 200 years have seen a shift toward just war in the moral focus concerning the state's use of force.[56]:59 Justification for war in the twenty-first century has become the ethic of intervention based on humanitarian goals of protecting the innocent.[57]

Key elements in criminal justice begin with the idea that God is the ultimate source of justice, and the judge of all, including those administering justice on earth.[58] Ethical knowledge and the moral character of those within a justice system are seen as central to the administration of justice with principles prohibiting "lying and deception, racial prejudice and racial discrimination, egoism and the abuse of authority" foremost.[59]:xx

Perception of the meaning of justice impacts a nation's criminal justice system, and the Christian understanding has continued to evolve throughout Christianity's history.[14]:325 Aristotle's classic definition of justice, giving each their due, entered into Christian ethics through scholasticism and Thomas Aquinas. For Aristotle and Aquinas that meant a hierarchical society with each receiving what was due according to their social status. This allows for the criminal justice system to be retributive, and fails to recognize a concept of universal human rights and responsibilities. After Aquinas, the social gospel redefined getting one's due as: "from each according to his ability, to each according to his need". Along these lines, justice had an egalitarian form while retaining male domination. Similarly, justice for slaves was defined as paternalistic care.[14]:325 "We can expect such issues to continue to occupy Christian ethics for years to come".[14]:325

In Christian ethics of the twenty-first century, capital punishment has become controversial, and there are Christian ethicists on both sides. Biblical ethicist Christopher Marshall says there are about 20 offenses that carry the death penalty in the Old Testament.[60]:46 "Evans explains that contemporary standards tend to view these laws of capital punishment as cavalier toward human life", however, the ancient ethic of covenantal community suggests the value of life was as much a communal value as an individual one.[60]:46–47 Contemporary society acknowledges that maintaining community requires rewards and punishments; order is established by the state's ability to enforce its requirements.[61]:18 Capital punishment can be seen as respect for the worth of the victim by calling for the equal cost to the offender; it can also be seen as respect for the offender, treating them as free agents responsible for their own choices who must bear the responsibility for their acts just as any citizen must.[62] Those in favor of abolishing the death penalty have sometimes elevated the condemned into an oppressed brotherhood, but John P. Conrad asserts that those on Death Row have committed terrible crimes for which they have seldom expressed regret and a few even took pride in.[61]:9 They present a danger to society, but the argument against capital punishment is not based on the criminal. It is based on a simple ethic: killing is wrong. It is not a permissible act, even for the state.[61]:10

In most ancient religions the primary focus is on human kind's relationship to nature, whereas in the Christian ethic, the primary focus is on the relationship with God as the "absolute moral personality".[20]:23 This is demonstrated as a focus on relationship itself as a primary concern in all Christian ethics.[63]

Traditional Christian ethics recognizes the command to "love thy neighbor" as one of the two primary commands called the "greatest commands" by Jesus.[64]:24 This reflects an attitude that aims at promoting another person's good in an "enlightened unselfishness".[65]:175 When the Pharisee asked Jesus: "Who is my neighbor?", Stanley J. Grenz says the questioner intended to limit the circle of those to whom this obligation was due, but Jesus responded by reversing the direction of the question into "To whom can I be a neighbor?".[65]:107 In the parable of the "Good Samaritan", the use of a racially despised and religiously rejected individual as an example of the good, defines a neighbor as someone who responds to anyone in need that one comes across.[66]

The full thought in Mark 12:31 is to love others as one loves oneself, and Christian ethics has not traditionally supported self-love as a good. According to Koji Yoshino, "altruistic love and self-love are not contradictory to each other. Those who don't love themselves cannot love others, nevertheless, those who ignore others cannot love themselves".[67]

The four primary views of Christian ethics on the roles of women include Christian feminism, which defines itself as a school of Christian theology which seeks to advance and understand the equality of men and women.[68] Christian egalitarianism argues that the Bible supports "mutual submission" without requiring a hierarchy of authority.[69] Complementarianism sees women as 'Ontologically equal, Functionally different'.[70] Biblical patriarchy asserts 1 Corinthians 14:34-35, 1 Timothy 2:11–15, and 1 Corinthians 11:2–16 in a hierarchical manner as part of an inerrant biblical authority.[71][72]:97

Jesus held women personally responsible for their own behavior: the woman at the well (John 4:16–18), the woman taken in adultery (John 8:10–11), and the sinful woman who anointed his feet (Luke 7:44–50), are all dealt with as having the personal freedom, and enough self-determination, to choose their own repentance and forgiveness.[73]:127 The New Testament names many women among the followers of Jesus as well as naming women in positions of leadership in the early church.[74][75][72]:54,112 Before the twelfth and thirteenth centuries, ordination was dedication to a particular role or ministry, and in this capacity, women in the church were ordained up until the 1200s.[76]:30 When theologians of this medieval period circumscribed the seven sacraments, they changed the vocabulary and gave the sacraments exclusively to male priests.[76]:30 In the nineteenth century, rights for women brought a wide variety of responses from Christian ethics with the Bible featuring prominently on both sides ranging from traditional to feminist.[77]:203 In the late twentieth century, the ordination of women became a controversial issue. Linda Woodhead states that, "Of the many threats that Christianity has to face in modern times, gender equality is one of the most serious".[78]

Among the early church fathers, married life was treated with some sensitivity as a relationship of love and trust and mutual service, contrasting it with non-Christian marriage as one where passions rule a "domineering husband and a lusty wife".[77]:24 In the synoptic Gospels, Jesus is seen as emphasizing the permanence of marriage, as well as its integrity: "Because of your hardness of heart, Moses allowed you to divorce your wives, but from the beginning it was not so".[79][80] Restriction on divorce was based on the necessity of protecting the woman and her position in society, not necessarily in a religious context, but in an economic context.[81] Paul concurred but added an exception for abandonment by an unbelieving spouse.[82]:351–354

Augustine wrote his treatise on divorce and marriage, De adulterinis coniuigiis, in which he asserts couples may only divorce on the ground of fornication (adultery) in 419/21, even though marriage didn't become one of the seven sacraments of the church until the thirteenth century.[82]:xxv Though Augustine confesses in later works (Retractationes) that these issues were complicated and that he felt he had failed to address them completely, adultery was the standard necessary for legal divorce until the modern day.[82]:110 The twenty-first century Catholic Church still prohibits divorce, but permits annulment (a finding that the marriage was never valid) under a narrow set of circumstances. The Eastern Orthodox Church permits divorce and remarriage in church in certain circumstances.[83] Most Protestant churches discourage divorce except as a last resort but do not actually prohibit it through church doctrine, often providing divorce recovery programs as well.[84][85]

Kyle Harper says ethics concerning sexuality was at the heart of Christianity's early clash with its surrounding pagan culture. The sexual-ethical structures of Roman society were built on status, and sexual modesty and shame were social concepts that were always mediated by gender and status.[86] :10,38[87][88]:7 Views on sexuality in the early church were diverse and fiercely debated within its various communities; these doctrinal debates took place within the boundaries of the ideas in Paul's letters, and in the context of an often persecuted minority seeking to define itself from the world around it. In his letters, Paul often attempted to find a middle way among these disputes, which included people who saw the gospel as liberating them from all moral boundaries, and those who took very strict moral stances.[88]:1–14,84–86,88

"The model of normative sexual behavior that developed out of Paul's reactions to the erotic culture surrounding him...was a distinct alternative to the social order of the Roman empire."[88]:85 For Paul, "the body was a consecrated space, a point of mediation between the individual and the divine."[88]:88–92 The ethical obligation for sexual self-control was placed equally on all people in the Christian communities, men or women, slave or free. In Paul's letters, porneia, (a single name for an array of sexual behaviors outside marital intercourse), became a central defining concept of sexual morality, and shunning it, a key sign of choosing to follow Jesus. Sexual morality could be shown by practicing chastity, which Paul defined as remaining virgin or having sex only within a marriage.[88]:88–92 Harper indicates this was a transformation in the deep logic of sexual morality as personal rather than social, spiritual rather than merely physical, and for everyone rather than solely for those with status.[88]:6,7

While Jesus made reference to some that have made themselves eunuchs for the kingdom of heaven,[89] there is no commandment in the New Testament that Jesus' disciples have to live in celibacy.[80] During the first three or four centuries, no law was promulgated prohibiting clerical marriage. Celibacy was a matter of choice for bishops, priests, and deacons.[80] In the twenty-first century, the Roman Catholic Church teachings on celibacy uphold it for monastics and priests.[90]

Protestantism has rejected the requirement of celibacy for pastors. Celibacy is primarily refraining from premarital sex until the joys of a future marriage. Some evangelicals, particularly older singles, desire a positive message of celibacy that moves beyond the "wait until marriage" message of abstinence campaigns. They seek a new understanding of celibacy that is focused on God rather than a future marriage or a lifelong vow to the Church.[91]

"Today, an uneasiness about sex continues to linger as a heritage from those early Christian efforts to cope with the sexual impulse".[92] In contemporary Christian ethics, there are a variety of views on the issues of sexual orientation and homosexuality. The many Christian denominations vary from condemning homosexual acts as sinful, to being divided on the issue, and to seeing it as morally acceptable. Even within a denomination, individuals and groups may hold different views. Further, not all members of a denomination necessarily support their church's views on homosexuality.[93] "Traditional societies place sex and gender in the context of community, family and parenthood; modern societies respect reciprocity, intimacy and gender equality".[47]:257

In the twenty-first century, Christian organizations reject slavery, but historically Christian views have varied, embracing both support and opposition.[94][95][96][97] Slavery was harsh and inflexible in the first century when Christian ethics began, and slaves were vulnerable to abuse, yet neither Jesus nor Paul order the abolition of slavery.[98] At this time, the Christian view was that morals were a matter of obedience to the ordained hierarchy of God and men.[99]:296 Paul was opposed to the political and social order of the age in which he lived, but his letters offer no plan for reform beyond working toward the apocalyptic return of Christ. He did indirectly articulate a social ideal through the Pauline virtues, and indirectly undermined the mistreatment of women, children and slaves through his teachings on marriage and his lifestyle. Paul's refusal to marry and set up a household that would require slaves, and his insistence on being self-supporting, was a model followed by many that "structurally attacked slavery by attacking its social basis, the household, and its continuity through inheritance from master to master".[99]:308–309

In the early 4th century, Roman law, such as the Novella 142 of Justinian, gave bishops (and priests) the power to free slaves by a ritual performed by that Christian bishop or a priest in a church. It is not known if baptism was required before this ritual.[100] Several early figures, such as Saint Patrick (415-493), Acacius of Amida (400-425), and Ambrose (337 – 397 AD) while not openly advocating abolition, made sacrifices to emancipate or free slaves.[101] Gregory of Nyssa (c. 335-394) went further and stated opposition to all slavery as a practice.[102][103] Later Saint Eligius (588-650) used his vast wealth to purchase British and Saxon slaves in groups of 50 and 100 in order to set them free.[104]

By the time of Charlemagne, while Muslims were coming onto the scene "as major players in a large-scale slave trade", slavery became almost non-existent in the West till the end of the central middle ages.[105]:38;167 Criticism of the trade in Christian slaves was not new, but at this time, opposition began to get wider support, seeing all those involved in the trade as "symbols of barbarity".[105]:39 Slavery in Africa existed for six centuries before the arrival of the Portuguese and the opening of the Atlantic slave trade.[106]:8 Economics drove it on from there, but the trade was abolished in the U.S. while it was still profitable and important to the American economy.[106]:188 Early abolitionist literature viewed the abolition of slavery as a moral crusade.[106]:188

Bioethics is the study of the life and health issues raised by modern technology that attempts to discover "normative guidelines built on sound moral foundations".[107]:vii This is necessary because the moral questions surrounding new medical technologies have become complex, important and difficult.[108]:9;11 With the tremendous benefits of medical advances, have come the "eerie forebodings of a future that is less humane, not more".[108]:12 Charges of abuses of technology in neo-natal intensive care units have already been leveled.[107]:93,94 Remedies for infertility enable researchers to create embryos as a disposable resource for stem cells. Manipulating the genetic code can prevent inheritable diseases and also produce, for those rich enough, designer babies "destined to be taller, faster and smarter than their classmates".[108]:12 Scripture offers no direct instruction for when a right to life becomes a right to death.[108]:14

The Catholic bioethic can be seen as one that rests on natural law. Moral decision making affirms the basic "goods" or values of life, which is built on the concept of a hierarchy of values, with some values more basic than others.[107]:20,17 For example, Catholic ethics supports self-determination but with limits from other values, say, if a patient chose a course of action that would no longer be in their best interests, then outside intervention would be morally acceptable.[107]:18 If there is conflict over how to apply conflicting values, then a proportionate reasoned decision which includes values such as preservation of life, human freedom, and lessening pain and suffering must be made by recognizing that not all values can be realized in these situations.[107]:19–20

The Protestant Christian ethic is rooted in the belief that agape love is its central value, and that this love is rooted in covenant fidelity expressed in pursuit of good for other persons.[107]:20–22 This ethic as a social policy may use natural law and other sources of knowledge, but in the Protestant Christian ethic, apape love must remain the controlling virtue that guides principles and practices.[107]:23 This Christian ethic determines the moral choice by what is the most love-embodying action within a situation. Actions that can be seen as unconditionally wrong, when they are acts of maximal love toward another, become unconditionally right.[107]:24

New technologies of prenatal testing, DNA therapy and other genetic engineering help many yet also offer ways in which "science and technology can become instruments of human oppression".[14]:303 Prenatal genetic testing has enabled couples to see the genetic make-up of their unborn children, "and in many cases they make decisions to end their pregnancies on the basis of such information".[107]:92 Genetic technologies can correct genetic defects, but the problem is that how one defines defect is often subjective. Parents might have certain expectations about gender, for example, and consider anything else as defective.[107]:118–120 In some Third World countries where "women have far fewer rights and female children are viewed as liabilities with bleak futures", genetic testing is widely used for sex selection, and some couples have terminated otherwise healthy pregnancies because the child was not the desired gender.[107]:121 Research into the gene for homosexuality could lead to prenatal tests that predict it, which could be particularly problematic in countries where homosexuals are considered defective and have no legal protection.[109] Such intervention is problematic morally, and has been characterized as "playing God".[107]:93,94

The general view of genetic engineering by Christian ethicists is stated by theologian John Feinburg. He reasons that since diseases are the result of sin coming into the world, and because Christian ethics asserts that Jesus himself began the process of conquering sin and evil through his healings and resurrection, "if there is a condition in a human being (whether physical or psychological) [understood as disease], and if there is something that genetic technology could do to address that problem, then use of this technology would be acceptable. In effect, we would be using this technology to fight sin and its consequences".[107]:120

"If one says that the central issue between conservatives and liberals in the abortion question is whether the fetus is a person, it is clear that the dispute may be either about what properties a thing must have in order to be a person, in order to have the right to life - a moral question - or about whether a fetus at a given stage of development... possesses the properties in question".[42]:50 Most philosophers have picked out the capacity for rationality, autonomy and self-awareness to describe personhood, but there are at least four possible definitions: in order to be a true person, a subject must have interests; possess rationality; be capable of action; and/or possess self-consciousness.[42]:53 A fetus fails to possess at least one and possibly two of these, and so it can be argued that the fetus is not a true person. From there, the argument can be moved on to justify infanticide as well. "Without assuming the Christian moral framework" concerning the sanctity of life, "the grounds for not killing persons do not apply to newborn infants. Neither classical utilitarianism nor preferential utilitarianism ... offer good reasons why infanticide should necessarily be wrong".[42]:44–46 P. Singer in Practical Ethics describes the Christian argument as "It is wrong to kill an innocent human being; a fetus is an innocent human being" therefore it is wrong to kill a fetus.[42]:46[110] However, the Christian ethic is more than a simple syllogism, it is "a narrative that includes the child in God's family, takes into account the entire context surrounding its birth, including the other lives involved, and seeks harmony with God's redeeming activity through Christ. It includes confidence in God's ability to sustain and direct those who put their trust in him".[42]:339

The Christian ethic concerning alcohol has fluctuated from one generation to the next. In the nineteenth century, the largest proportion of Christians in all denominations resolved to remain alcohol free. While it is true that some contemporary Christians, including Pentecostals, Baptists and Methodists, continue to believe one ought to abstain from alcohol, the majority of contemporary Christians have determined that moderation is the better approach.[111][112]:4–7 Alcohol misuse is a "contemporary social problem of enormous economic significance, which exacts a high toll in human suffering".[112]:1 All persons must, directly and indirectly, determine their ethical response to alcohol's enormous popularity and widespread acceptance in the face of its social and medical harm.[112]:4 The Christian ethic takes seriously the power of addiction to "hold people captive, and the need for an experience of a gracious 'Higher Power' as the basis for finding freedom".[112]:199

The arguments used to defend physician-assisted suicide (PAS) are concepts of justice and mercy that can be described as a "minimalist" understanding of the terms. A minimal concept of justice respects autonomy, protects individual rights, and attempts to guarantee that each individual has the right to act according to their own preferences, but none of us are as independent or autonomous as this definition pretends. This minimalist view doesn't recognize the significance of covenant relationships and doesn't define what is good for the dying Christian; it only defines what limits to exercise as we look for what is good.[113]:348;350 Empathy toward another's suffering tells us to do something but not what to do. Such a minimalist understanding of mercy can justify almost anything.[113]:349 Once killing becomes an act of mercy, it could become difficult not to exercise such mercy toward those who have not achieved, or are past, autonomy: the handicapped, the elderly, children.[113]:350 In the Christian ethic, "life and its flourishing are gifts of God, but they are not the ultimate good, and neither are suffering and death the ultimate evils. One need not use all of one's resources against them. One need only act with integrity in the face of them".[113]:352

David VanDrunen explains that modern technology has treatments that enable a persistent vegetative state (PVS) which has led to questions of euthanasia and the controversial distinction between killing and letting die.[108]:197 PVS patients are in a permanent state of unconsciousness due to the loss of higher brain function; the brain stem remains alive, so they breathe, but swallowing is a voluntary reflex, so they must receive artificial nutrition and hydration (ANH) to survive. These patients can be without other health problems and live for extended periods. Most ethicists conclude it is morally sound to decline ANH for such a patient, but some argue otherwise based on defining when death occurs.[108]:232

The "doctrine of creation creates a presumption in favor of environmental conservation".[14]:327 As Francis Schaeffer said of the Christian ethic: "We are called to treat nature personally".[114]:127 The incarnation shows God loves material reality, not just spirit.[114]:129 The Christian ethic, with its concepts of redemption of all physical reality and its manifestation in community and relation to others, is a vital corrective to modern individualism which devalues both human and non-human distinctiveness.[114]:209

The twenty-first century has seen an increased concern over the possibly devastating effects of human civilization on the environment: global warming, pollution, soil erosion, deforestation, species extinction, over-population, and over-consumption are all factors in this crisis.[114]:xi There appears to be a strong scientific consensus that industrialized civilization has emitted enough carbon dioxide into the atmosphere to create a greenhouse effect causing global warming, yet debate rages primarily over the economic effects of limiting development.[14]:312–313 Michael Northcott says both issues will have to be dealt with: the reorientation of modern society toward recognizing the biological limits of the planet will not occur without a related quest for justice and the common good.[114]:xiii

Various criteria have been proposed for establishing the boundaries of personhood between the human and the non-human, but it has become widely accepted that personhood is linked to concepts of rationality and morality.[42]:1,2 To qualify as a being with rights, H. J. McCloskey and Joel Feinberg have asserted that one must have "interests".[42]:301 R. G. Frey, in his monograph Interests and Rights, argues the problem here is in defining "interests". If the prerequisite for having "interests" includes self-consciousness, or minimal language for communication of those interests, then the case against animals having interests, and therefore rights, is strong.[42]:302 Stanley Rudman says a strict interpretation of personhood would require animals to assume moral obligations for which they have no ability.[42]:319

Rudman argues that, what it means to be human, cannot be determined based on two qualities alone without reference to the full spectrum of physical, mental, social and spiritual aspects of human life.[42]:337 In the Christian ethic, personhood is related to the nature of God, who is understood in terms of community and inter-relationship.[42]:1 In this view, personhood has both genetic and environmental dimensions, and the process of becoming more human is impossible without the help of others; it requires community.[42]:338 A definition of personhood which emphasizes community, without disparaging reason, is preferable to one which emphasizes rationality above all else.[42]:335–337

Within the Christian ethic, the nature of moral community isn't limited to a community of equals: humans are not equal to God yet have community with him.[42]:319 Animals should be included in the moral community without being required to be regarded as persons.[42]:339 Based on such convictions, which include the future transformation and liberation of all creation, a Christian view is obligated to take animal welfare seriously.[42]:319 Therefore, the Christian ethic sees an emphasis on animal welfare as a better approach than the use of concepts of personhood and divine rights for addressing inhumane treatment of animals.[42]:319