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 seventh and final letter is sent to the Church of Laodicea (3:14-22). If the previous letter was very positive, this is the exact opposite.