According to the author of the Book of Revelation, the concluding book of the Bible, Jesus Christ directed letters to seven Churches in present-day western Turkey.
All these letters have the same structure. They begin with the name of the Church. Then Jesus uses a different image in each one to identify himself after which he makes a judgment about that Church. He provides a particular exhortation for that Church followed by a general exhortation to all who will hear and a promise of a reward to the victors.
Jesus’ third letter is addressed to the Church at Pergamum (2:12-17), which in Roman times had been a center of emperor worship.