Revelation
Purpose of Writing: The Revelation of Jesus Christ was given to John by God “to show his servants what must soon take place.” This book is filled with mysteries about things to come. It is the final warning that the world will surely end and judgment will be certain. It gives us a tiny glimpse of heaven and all of the glories awaiting those who keep their robes white. Revelation takes us through the great tribulation with all its woes and the final fire that all unbelievers will face for eternity. The book reiterates the fall of Satan and the doom he and his angels are bound for. We are shown the duties of all creatures and angels of heaven and the promises of the saints that will live forever with Jesus in the New Jerusalem. Like John, we find it hard to describe what we read in the book of Revelation.
Reference: https://www.gotquestions.org/Book-of-Revelation.html