Apocalyptic religious literature is regarded as a distinct branch of literature. This genre has several characteristic features. The common elements that all of these apocalyptic books seem to have are the stark contrast of forces of evil and forces of good lining themselves up against one another in a final cosmic conflict that spreads throughout the whole earth, followed by the overthrow by God.
Revelation of mysteries
It is a revelation of mysteries, things which lie beyond the ordinary range of human knowledge. God gives to select prophets or saints instruction in regard to hidden matters, whether things altogether foreign to human experience, or merely events in human history which have not yet come to pass.
Some of the secrets of heaven are disclosed, in greater or less detail: the purposes of God; the deeds and characteristics of angels and evil spirits; the explanation of natural phenomena; the story of Creation and the history of early mankind; impending events, especially those connected with the future of Israel; the end of the world; the final judgment, and the fate of mankind; the messianic age; pictures of heaven and hell. In the Book of Enoch, the most comprehensive Jewish apocalypse, the revelation includes all of these various elements.
Disclosure through a dream or vision
The disclosure of hidden wisdom is made through a vision or a dream. Because of the peculiar nature of the subject-matter, this is evidently the most natural literary form. Moreover, the manner of the revelation, and the experience of the one who receives it, are generally made more or less prominent. Usually, though not always, the account is given in the first person. There is something portentous in the circumstances, corresponding to the importance of the secrets about to be disclosed. The element of the mysterious, often so prominent in the vision itself, is foreshadowed in the preliminary events. Some of the persistent features of the "apocalyptic tradition" are connected with the circumstances of the vision and the personal experience of the seer.
The primary example of apocalyptic literature in the Hebrew Bible is the book of Daniel. As Daniel after long fasting stands by the river, a heavenly being appears to him, and the revelation follows (Daniel 10:2ff). John, in the New Testament Revelation (1:9ff), has a like experience, told in very similar words. Compare also the first chapter of the Greek Apocalypse of Baruch; and the Syriac Apocalypse, vi.1ff, xiii.1ff, lv.1-3. Or, as the prophet lies upon his bed, distressed for the future of his people, he falls into a sort of trance, and in "the visions of his head" is shown the future. This is the case in Dan. 7:1ff; 2 Esdras 3:1-3; and in the Book of Enoch, i.2 and following. As to the description of the effect of the vision upon the seer, see Dan. 8:27; Enoch, lx.3; 2 Esd. 5:14.
Angels bear revelation
The introduction of Angels as the bearers of the revelation is a standing feature. God does not speak in person, but gives His instruction through the medium of heavenly messengers, who act as the seer's guide.
There is hardly an example of a true Apocalypse in which the instrumentality of angels in giving the message is not made prominent. In the Assumption of Moses, which consists mainly of a detailed prediction of the course of Israelite and Jewish history, the announcement is given to Joshua by Moses, just before the death of the latter. So, too, in the Sibylline Oracles, which are for the most part a mere foretelling of future events, the Sibyl is the only speaker. But neither of these books can be called truly representative of apocalyptic literature in the narrower sense (see below). In another writing which has sometimes been classed as apocalyptic, the book of Jubilees, an angel is indeed the mediator of the revelation, but the vision or dream element is wanting. In this case, however, the book is not at all apocalyptic in its nature.
Deals with the future
In the typical compositions of this class the chief concern of the writer is with the future. The Apocalypse is primarily a Prophecy usually with a distinctly religious aim, intended to show God's way of dealing with men, and His ultimate purposes. The writer presents, sometimes very vividly, a picture of coming events, especially those connected with the end of the present age. Thus, in certain of these writings the subject-matter is vaguely described as "that which shall come to pass in the latter days" (Dan. 2:28; compare verse 29); similarly Dan. 10:14, "to make thee understand what shall befall thy people in the latter days"; compare Enoch, i.1, 2; x.2ff. So, too, in Rev. 1:1 (compare the Septuagint translation of Dan. 2:28ff), "Revelation . . . that which must shortly come to pass." Past history is often included in the vision, but usually only in order to give force and the proper historical setting to the prediction, as the panorama of successive events passes over imperceptibly from the known to the unknown. Thus, in the eleventh chapter of Daniel, the detailed history of the Greek empire in the East, from the conquest of Alexander down to the latter part of the reign of Antiochus Epiphanes (verses 3-39, all presented in the form of a prediction), is continued, without any break, in a scarcely less vivid description (verses 40-45) of events which had not yet taken place, but were only expected by the writer; viz., the wars which should result in the death of Antiochus and the fall of his kingdom. All this, however, serves only as the introduction to the remarkable eschatological predictions in the twelfth chapter, in which the main purpose of the book is to be found. Similarly, in the dream recounted in 2 Esd. 11 and 12, the eagle, representing the Roman Empire, is followed by the lion, which is the promised Messiah, who is to deliver the chosen people and establish an everlasting kingdom. The transition from history to prediction is seen in xii.28, where the expected end of Domitian's reign -- and with it the end of the world -- is foretold. Still another example of the same kind is Sibyllines, iii.608-623. Compare perhaps also Assumptio Mosis, vii-ix. In nearly all the writings which are properly classed as apocalyptic the eschatological element is prominent. In fact, it was the growth of speculation regarding the age to come and the hope for the chosen people which more than anything else occasioned the rise and influenced the development of this sort of literature.
The mysterious or monstrous
The element of the mysterious, apparent in both the matter and the manner of the writing, is a marked feature in every typical Apocalypse. The literature of visions and dreams has its own traditions, which are remarkably persistent; and this fact is unusually well illustrated in the group of Jewish (or Jewish-Christian) writings under consideration.
This apocalyptic quality appears most plainly (a) in the use of fantastic imagery. The best illustration is furnished by the strange living creatures which figure in so many of the visions--"beasts" in which the properties of men, animals, birds, reptiles, or purely imaginary beings are combined in a way that is startling and often grotesque. How characteristic a feature this is may be seen from the following list of the most noteworthy passages in which such creatures are introduced: Dan. 7:1-8, 8:3-12 (both passages of the greatest importance for the history of apocalyptic literature); Enoch, lxxxv.-xc.; 2 Esd. 11:1-12:3, 11-32; Greek Apoc. of Bar. ii, iii; Hebrew Testament, Naphtali's, iii.; Rev. 6:6ff (compare Apoc. of Bar. [Syr.] li.11), ix.7-10, 17-19, xiii.1-18, xvii.3, 12; the Shepherd of Hermas, "Vision," iv.1. Certain mythical or semimythical beings which appear in the Old Testament are also made to play a part of increasing importance in these books. Thus "Leviathan" and "Behemoth" (Enoch, lx.7, 8; 2 Esd. 6:49-52; Apoc. of Bar. xxix.4); "Gog and Magog" (Sibyllines, iii.319ff, 512ff; compare Enoch, lvi.5ff; Rev. 20:8). As might be expected, foreign mythologies are also occasionally laid under contribution (see below).
The apocalyptic quality is seen again (b) in the frequent use of a mystifying symbolism. This is most strikingly illustrated in the well-known cases where gematria is employed for the sake of obscuring the writer's meaning; thus, the mysterious name "Taxo," Assumptio Mosis, ix. 1; the "number of the beast," 666, of Rev. 13:18; the number 888 ('Iησōῦς), Sibyllines, i.326-330. Very similar to this is the frequent enigmatic prophecy of the length of time which must elapse before the events predicted come to pass; thus, the "time, times, and a half," Dan. 12:7; the "fifty-eight times" of Enoch, xc.5, Assumptio Mosis, x.11; the announcement of a certain number of "weeks" or days (without specifying the starting-point), Dan. 9:24ff, 12:11, 12; Enoch xciii.3-10; 2 Esd. 14:11, 12; Apoc. of Bar. xxvi-xxviii; Rev. 11:3, 12:6; compare Assumptio Mosis, vii.1. The same tendency is seen also in the employment of symbolical language in speaking of certain persons, things, or events; thus, the "horns" of Dan. 7 and 8; Rev. 17 and following; the "heads" and "wings" of 2 Esd. xi and following; the seven seals of chapter 6 of Revelations; trumpets, 8; bowls, 16; the dragon, Rev. 12:3-17, 20:1-3; the eagle, Assumptio Mosis, x.8; and so on.
As typical examples of more elaborate allegories -- aside from those in Dan. 7, 8 and 2 Esd. 11, 12, already referred to-may be mentioned: the vision of the bulls and the sheep, Enoch, lxxxv and following; the forest, the vine, the fountain, and the cedar, Apoc. of Bar. xxxvi and following; the bright and the black waters, ibid. liii and following; the willow and its branches, Hermas, "Similitudines," viii. To this description of the literary peculiarities of the Jewish Apocalypse might be added that in its distinctly eschatological portions it exhibits with considerable uniformity the diction and symbolism of the classical Old Testament passages. As this is true, however, in like degree of the bulk of late Jewish and early Christian eschatological literature, most of which is not apocalyptic in the proper sense of the word, it can hardly be treated as a characteristic on a par with those described above.