“At thy right hand there are pleasures for evermore” (Ps. 16: 11)
“I was in the Spirit on the Lord’s day, and heard behind me a great voice, as of a trumpet, Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea.” (Revelation 1:10–11).
John begins to tell us the beginning of the vision. He had been exiled to Patmos, and on a particular Lord’s Day, he was in the Spirit. This tells us, incidentally, that there is a day set apart for the Lord, the first day of the week, the day He rose from the dead, which is to say, Sunday. John was in the Spirit, which is to say he was in a trance, capable of seeing the vision that he saw.
While in that condition, he heard a great voice behind him and he turned and looked. This is a something we see later in the book of Revelation. He first hears, then turns, and looks at what he heard (Rev. 7: 4, 9). The speaker behind him had a great voice, clear as a trumpet, and He identified Himself as Jesus Christ. The way He did this was by calling Himself the Alpha and Omega (the first and last letters in the Greek alphabet), and then repeating it another way by saying He was the first and the last.
John is then given his commission—he is told to write down in a book what he sees in the vision, and then he is to send that book to the seven church in the province of Asia. Those seven churches, in order, were Ephesus, Smyrna, Pergamos, Thyatira, Sardis, Philadelphia, and Laodicea.