A famous book in which St. John the Divine concealed all that he knew.
The revealing is done by the commentators who know nothing.
Note: My answer below reflects my 450+ page Harvard doctoral thesis on Christian prophecy.
As a literary genre, the Apocalypse of John of course qualifies as the earliest extant Christian apocalypse. But one thing that makes Revelation distinct is the fact that all the other Jewish and Christian apocalypses are pseudonymous. I chuckle every time I recall my Princeton NT professor’s opening discussion of authorship in his course on Revelation. He said dryly, “The author says his name is John. He should know what his own name is.” John’s apocalypse is also unique in that its author is a prophet and his work is a literary hybrid in the sense that it contains prophetic oracles and other prophetic speech. Most importantly, each of the letters to the 7 churches represents a Prophecy of Salvation structural form that can be found in OT prophecy and in other early Christian prophecy.
Beyond semantics, this distinction between apocalyptic and prophecy is important in this sense. A prophet is “a figure divinely authorized to control the conditions of divine forgiveness and redemptive security.” So the future is not normally fixed for a prophet because, if believers meet God’s conditions for repentance, the dogmatic uttered predictions of judgment are normally then suspended. The same cannot normally be said of apocalyptic writings.