Jesus sent his angel with testimony for the churches (Rev 22:16)

The book of Revelation is actually a letter. Written by a Christian leader named John who had been exiled to the island of Patmos, it was sent to seven congregations in Asia Minor (1). The book begins by describing conditions in each of the seven churches. Some were challenged by persecution, others by complacency, and still others by teachings that approved of eating meat offered to idols and practicing immorality. Then presents readers with a scene in which the heavenly hosts worship God on the throne and Christ the Lamb who was slain (4-5). The book does not provide a linear description of the end times, but presents several cycles of visions that warn about coming tribulations. The adversaries of God's people are depicted as a Beast and a Harolot, who are finally destroyed. At the end of each cycle the readers return to the heavenly throne room (7:9-17; 11:15-19; 15:2-4; 19:1-8). The final chapters culminate in the new Jerusalem, the city of God (21:1-22:5). Through its warnings and promises the book seeks to bring readers to renewed faith in God and the Lamb, who are the Alpha and the Omega, the beginning and the end (1:8; 22:13).

Rev 5:6-14 - The Lamb of God
Rev 13:1-8 - The Beast
Rev 19:11-21 - The Battle
Rev 21:1--22:5 - New Jerusalem