An apocalypse (Ancient Greek: ἀποκάλυψις apokálypsis, from of/from: ἀπό and cover: καλύψη, literally meaning "from cover") is a disclosure or revelation of great knowledge. In religious concepts an apocalypse usually discloses something very important that was hidden or provides what Bart Ehrman has termed, "A vision of heavenly secrets that can make sense of earthly realities".[1] Historically, the term has a heavy religious connotation as commonly seen in the prophetic revelations of eschatology obtained through dreams or spiritual visions. It is believed by many Christians that the biblical Book of Revelation depicts as an "apocalypse", the complete destruction of the world, preceding the establishment of a new world and heaven. However, there is also another interpretation of the Book of Revelation in which the events predicted are said to refer to the destruction of Jerusalem in A.D. 70 by the Roman armies of Titus. This second view is known as the Preterist view of eschatology.

In all contexts, the revealed events usually entail some form of an end time scenario or the end of the world – or revelations into divine, heavenly, or spiritual realms. There are many other books from the Jewish and Christian world that can be classified as apocalypses. In addition, other books of the Bible contain passages pertaining to an apocalypse or to apocalyptic circumstances.

The Greek word apokálypsis has become particularly associated with the last book of the New Testament entitled "Revelation" and also known as "the Apocalypse" or as "the Apocalypse of John". The term is also included in the title of some non-biblical canon books involving revelations. Today, English-speakers commonly refer to any larger-scale catastrophic event or chain of detrimental events to humanity or nature as "an apocalypse" or as "apocalyptic".

A revelation may be made through a dream, as in the Book of Daniel, or through a vision, as in the Book of Revelation. In biblical terms, a revelation is something shown to humans by God: Other words used to describe revelation include: apocalypse, prophecy, unveiling. Fasting, mainly as part of a spiritual discipline, can lead one into an apocalyptic prophetic vision.[2] One example of this is found in the Book of Daniel which is the first apocalypse in the Protestant Bible.[3] After a long period of fasting,[4] Daniel is standing by a river when a heavenly being appears to him, and the revelation follows (Daniel 10:2ff). Apocalyptic visions or dreams show hidden information/truth about God, human life and the spiritual world. These visions or dreams usually show insights about life after death. A part about God's final judgement deals with forces of evil and forces of good. In the Bible God defeats an evil force forever and bring justice and mercy to the world. Rev 20–22,[5] and the article

Apocalyptic writing often makes wide use of symbolism. One instance of this occurs where gematria is employed, either for obscuring the writer's meaning or enhancing it; as a number of ancient cultures used letters also as numbers (i.e., the Romans with their use of "Roman numerals"). Thus the symbolic name "Taxo," "Assumptio Mosis", ix. 1; the "Number of the Beast" (616/666), in the Book of Revelation 13:18;[6] the number 666 ('Iησōῦς), Sibyllines, i.326–30.

Similar is the frequent prophecy of the length of time through which the events predicted must be fulfilled. Thus, the "time, times, and a half," Daniel 12:7 which has been taken to be 3½ years in length by Dispensationalists;[7] the "fifty-eight times" of Enoch, xc.5, "Assumptio Mosis", x.11; the announcement of a certain number of "weeks" or days, which starting point in Daniel 9:24, 25 is "the going forth of the commandment to restore and to build Jerusalem unto the Messiah the Prince shall be seven weeks",[8] a mention of 1290 days after the covenant/sacrifice is broken (Daniel 12:11),[9] 12; Enoch xciii.3–10; 2 Esdras 14:11, 12; Apocalypse of Baruch xxvi–viii; Revelation 11:3, which mentions "two witnesses" with supernatural power,[10] 12:6;[11] compare Assumptio Mosis, vii.1.

Symbolic language also occurs in descriptions of persons, things or events; thus, the "horns" of Daniel 7 and 8;[12] Revelation 17[13] and following; the "heads" and "wings" of 2 Esdras xi and following; the seven seals of Revelation 6;[14] trumpets, Revelation 8;[15] "vials of the wrath of God" or "bowl..." judgments, Revelation 16;[16] the dragon, Revelation 12:3–17,[17] Revelation 20:1–3;[18] the eagle, Assumptio Mosis, x.8; and so on.

In the Hebrew Old Testament some pictures of the end of the age were images of the judgment of the wicked and the glorification of those who were given righteousness before God. In the Book of Job and in some Psalms the dead are described in these Hebrew texts as being in Sheol, awaiting the final judgment. The wicked will then be consigned to eternal suffering in the fires of Gehinnom, or the lake of fire mentioned in the Christian Book of Revelation.[16][19][20][21][22]