The author of the book of the Revelation names himself 4 times in his book by the name John (cf. Jn. 1:1,4,9; and Jn. 22:8). It is obvious from chapter 21:2 that the author is an eye-witness to the Ministry of Jesus Christ. He calls himself by several titles; he calls himself a slave of Jesus Christ, a fellow-slave, a brother, and a prophet, and he calls his book a prophecy. It’s a specialized kind of literature. It’s a prophetic literature now we know from history as apocalyptic literature. The strongest and the one that has the most evidence points to the apostle John, son of Zebedee as the John who claims authorship of this book; although some think it’s John Mark, while others say it’s John the Elder. Whichever John doesn’t really matter, we still believe it’s Scripture because of our presupposition of faith in the canonization process. The setting is obviously a time of terrible persecution (emperor worship) during the reign of Domitian, wherein the author writes this message of Revelation to 7 historical churches in the Roman province of Asia, which is modern Western Turkey. Although, i think this message of Revelation relates to all churches of all ages, contrary to popular belief that it deals with the different ages of the church. I think the letter deals with different aspects of church life and faith warnings, as well as admonitions, as well as blessings, and I think it applies to all the church as she goes through similar but different periods in history.
The exact occasion is persecution caused by the separation of the local churches from the synagogues. Rabbinical Judaism was the legal religion in the Roman Empire, but in 70AD after the rabbi’s met and set their own canon, they began to install synagogue oaths that made their adherents to the synagogues curse Christ. This really finally separated Judaism and Christianity, and Christianity began to be dealt with as an illegal sect and not simply a part of Judaism. We learn from history that the Roman Emperors began to use the word “kurios” or Lord for themselves beginning with Octavian, but particularly Nero. But the Christian could not say Caesar is “kurios” because they have reserved that term uniquely for Jesus of Nazareth. And though it really was more of a pledge of allegiance with divine implications, the Christians could not do it and so there was persecution. The purpose of Revelation is to show God’s sovereignty in human history particularly in times of stress and persecution. Perhaps that’s why we don’t understand it, is because we’re so busy making millenial charts on how it’s all going to happen in detail, we somehow miss the major thrust, which is God telling His people, “I’m in control. I know what’s happening, I’ll bring it to pass in My time in, My way, trust Me!”