The Letters to the seven churches
Found this explanation of The Letter to the angels of the churches
The letters to the churches in Revelation are addressed to the “angel” of each church. The word angel literally translates as “messenger”, as angels were God’s messengers prior to Christ. So as Christ sends His letters to each church, He addresses them to the angel of each church suggesting that an angelic messenger will ensure the message is delivered to that church as Christ expected.
That detail assures the reader that these messages did, in fact, reach their intended audiences, even though John was isolated on Patmos and unable to travel. Somehow, these letters were delivered as required, and the angels of each church were charged by Christ in accomplishing that task. This detail further validates the trustworthiness of what John wrote and the authority of Christ to lead and guide His Church even from Heaven.
This is the book that I am using in the Study of Revelation
