In Revelation 1:2 John says that he is a witness to the word of God and to the testimony of Jesus Christ. In the verse 9b he repeats the same thing by saying that he was on the island of Patmos because of the word of God and the testimony of Jesus Christ. In between in verse 5 John describes Jesus as Faithful Witness. In Revelation 19:13 says about Jesus that His name is Word of God. John 12:49-50 "For I did not speak on my own, but the Father who sent me commanded me to say all that I have spoken. I know that his command leads to eternal life. So whatever I say is just what the Father has told me to say." John 5:19 Jesus gave them this answer: "Very truly I tell you, the Son can do nothing by himself; he can do only what he sees his Father doing, because whatever the Father does the Son also does. John is seeing and describing Jesus as the faithful witness. Faithful witness to the Word of God, for He, Himself is called the Word of God, Jesus is a faithful witness