That is why Revelation 5, the vision of the Lamb opening the scroll, is the pivot point of the book. Of course, the Messiah's return will be vital to God's working out of history. Revelation looks to this event with anticipation as well. But Revelation says Christians need not depend on some saving event in the future. God has already acted decisively in history through himself as incarnate in Jesus.
Revelation is different from Jewish apocalyptic writings in several other ways as well.
Besides being prophecy and revelation, John's work is grounded in current history. Revelation, then, is a unique kind of writing. Nevertheless, Revelation does not read like a letter or homily. It is difficult to identify which complex literary type the author had in mind in writing the book. Our understanding of Revelation is also complicated by the fact that the apocalypse as a literary form does not exist in our time.