The greeting is addressed to the seven churches of Asia for whom the book was written.
Revelation 1:4. seven churches, i.e. Ephesus, Smyrna, Pergamum, Thyatira, Sardis, Philadelphia, Laodicea. Asia: not in the modern sense but the Roman province, which extended along the western coast-line of what is now known as Asia Minor. which was, etc.: this phrase describes the eternity of God. He is Lord of the past, the present, and the future. the seven spirits: a startling expression. We expect a reference to the Holy Spirit as in the benediction in 2 Corinthians 13:14. Many scholars think the writer uses this phrase to describe the Holy Spirit in His plenitude and perfection, and with the intention of signifying that each of the seven churches has its special impartation. But it is doubtful whether the Book of Revelation has reached the doctrine of the Holy Spirit as we understand it, and the phrase may refer to the seven angels of the presence (cf. Revelation 4:5). [If the seven spirits are not to be identified with the Holy Spirit, it is unjustifiable to say, with Bousset, that Christ is placed in the same rank as a similar heavenly being. This is inconsistent with the place elsewhere given to Him in the book. That He is mentioned last is due to the author's intention to speak more fully of Him, and he thus avoids the awkwardness of interpolating the description of Him into the middle of his trinitarian formula. 2 Corinthians 13:14 shows that nothing can be inferred from order as to rank. A. S. P.]
Revelation 1:5. faithful witness: cf. John 18:37, I am come into the world that I may bear witness, but the word may mean martyr, and there may be an allusion to the death of Christ. firstborn of the dead: cf. 1 Corinthians 15:20 *, Colossians 1:18. Unto him: the first of many doxologies (cf. Revelation 4:8, Revelation 5:9). loosed us: AV washed us. The presence or absence of a single letter in a Greek word accounts for the difference in the two versions. [Hebrew ritual of purification includes washing with water, and sprinkling with blood. It knows nothing of washing in blood, so that the AV reading is on that ground highly improbable. In Revelation 7:14 render through the blood of the Lamb; the words are not closely connected with washed. A. S. P.]
Revelation 1:6. kingdom. priests: the ideal represented by this phrase is the union of the royal and the priestly prerogatives in one set of persons. The king and the priest represent the two highest offices, and here these are combined in the position promised to the Christian (cf. Exodus 19:6; 1 Peter 2:9).
Revelation 1:7. with the clouds: cf. Daniel 7:13. which pierced him: the phrase, as in John 19:37, is borrowed from Zechariah 12:10. We have here a point of contact between Rev. and the Fourth Gospel.
Revelation 1:8. Alpha and Omega: the first and last letters in the Greek alphabet, and so used to represent the beginning and the end. Here applied to God, but in Revelation 1:11 (AV) and Revelation 22:13 to Christ.