What are the characteristics of what is called "apocalyptic" literature? Why would an author use this literary style? Does apocalyptic literature envision the end of the cosmos? If not, what kind(s) of thing(s) does apocalyptic literature envision?
Apocalyptic literature developed as a distinctly Jewish genre. It began with them and developed with them. The Christians continued to use it.
Stages of the history of Apocalyptic Literature
7 Characteristics of Apocalyptic Literature
James Jordan writes:
"...there is no apocalyptic literature in the Bible. Apocalypticism, originally a form of Jewish gnosticism, taught that the world is coming to an end and therefore we should retreat and wait for deliverance. (Apocalypticism is one of the major heresies of American evangelicalism, of course.) The prophetic passages of the Bible teach the opposite. They always teach that the world is coming to a new beginning, and therefore we must get to work."
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So, apocalyptic is name presumably taken from the Revelation and applied to highly symbolic texts. The problem is that, beneath the symbolism, the content of the biblical symbolic texts is very different to the uninspired texts, which seem to have taken the style of the prophets and used it for something quite different. Once we identify this difference in content, the biblical texts outshine the bandwagon "Jewish fables," and their difference in purpose is more easily seen. The Olivet discourse, the OT prophets and Revelation, are not describing the end of the world but only the end of the old order and the beginning of the new. Revelation, like Ezekiel for instance, is a covenant lawsuit against the covenant people, and describes their "death and resurrection" as a new Israel. The last days are only ever the last days of the old order.
The other issue is that John's "apocalypse" is in fact a "revealing." Paul speaks of his Gospel as a new "revealing," a cutting away of the old, replacing the circumcision, tearing down the veil and the wall of the Law (the Jew-Gentile divide) forever. This can only happen once (AD70), so maintaining "apocalypticism" as a genre is misleading. Better simply to speak of "symbolic" books.
Finally, biblical symbolism is systematic. Every Covenant cycle is the Bible has the same shape, and predictions of the next cycle, or Covenantal event, invariably make allusions to the previous ones (such as the allusions to the Great Flood and the Exodus in Isaiah 11, and Jesus' references to Isaiah 13 in Matthew 24 concerning the end of the Herodian "Babylon.") The uninspired texts lack this kind of purpose. They take on the stylistic appearance of the prophetic much as the book of Mormon sounds like the King James Bible.