The book of Revelation is the final book of the Bible and sits in the New Testament; it has 22 chapters in the King James Version.
Revelation is traditionally attributed to John. Revelation opens by identifying itself as "The Revelation of Jesus Christ" given to John on the island of Patmos, and contains letters to seven churches (chapters 2-3) followed by a series of visions. A well-known passage from this book is Revelation 3:20. Read the full book at Revelation.