Charles Ellicott Commentary Revelation 1:2

"who bare witness of the word of God, and of the testimony of Jesus Christ, [even] of all things that he saw." — Revelation 1:2 (ASV)

Who bore record.—Elsewhere as well as here. And he tells us of what he bore record—of the Word of God. The writer declares that the substance of his testimony and witness had been this Word of God. We have here an indication of what the general character of his teaching had been. It evidently had been a teaching emphasizing that aspect of truth which is so forcibly set before us in the Fourth Gospel and the Epistles bearing the name of John. (John 1:1; John 1:14; 1 John 1:1, and others. Note also that the words “record,” “testimony,” “witness,” found in this verse, recur in the Gospel and Epistles. Compare John 5:31-40; John 19:35; John 21:24.)