New International Version
who testifies to everything he saw--that is, the word of God and the testimony of Jesus Christ.

American Standard Version
who bare witness of the word of God, and of the testimony of Jesus Christ, even of all things that he saw.

Berean Study Bible
who testifies to everything he saw. This is the word of God and the testimony of Jesus Christ.

Douay-Rheims Bible
Who hath given testimony to the word of God, and the testimony of Jesus Christ, what things soever he hath seen.

English Revised Version
who bare witness of the word of God, and of the testimony of Jesus Christ, even of all things that he saw.

King James Bible
Who bare record of the word of God, and of the testimony of Jesus Christ, and of all things that he saw.

World English Bible
who testified to God's word, and of the testimony of Jesus Christ, about everything that he saw.

Young's Literal Translation
who did testify the word of God, and the testimony of Jesus Christ, as many things also as he did see.

Revelation 1:2 Additional Translations ...