(Rev. 1:9-18) The vision of the Son of Man, in His dignity as the Judge, is introductory to the messages which give His judgment on the Seven Churches. We do well to linger over the vision, for it is the greatness of the Speaker that gives value to His words. Thus the deeper our sense of the glory of the One who speaks, the more heed shall we give to that which He utters.
(Vss. 9-10). Before we see the vision of Christ, we learn that such sights call for special circumstances; they require a suited condition of soul, and their appropriate season. Thus it is that John finds himself in circumstances of trial, and, though truly in the kingdom as subject to Christ, yet not in the kingdom and glory, but, in the kingdom and patience in Jesus. Furthermore, he is banished to the barren Isle of Patmos. If, however, he is banished to some desolate spot by the decrees of man, it is that, withdrawn from every other influence, he may receive the Word of God and the testimony of Jesus Christ. How often, in the history of God's people, times of trial have become seasons of spiritual illumination. As another has pointed out, Joseph must go to the prison to become a revealer of secrets: David must be driven into the dens of the earth to sing his sweetest songs: Paul must suffer imprisonment to receive his highest revelations; and John must go to his Patmos prison to hear words, and see visions, that mortal had never heard nor seen before.

https://youtube.com/watch?v=cD0EIGNe5Nc