John 21:24
This is the disciple who testifies about these things, and who wrote these things. And we know that his testimony is true.
John 19:35
And he who has seen has testified, and his testimony is true. And that man knows that he speaks true, so that ye may believe.
3 John 1:12
Demetrius has been testified by all, and by the truth itself. But we also testify, and ye know that our testimony is true.
John 15:27
And ye also testify, because ye have been with me from the beginning.
1 John 1:1-2
What was from the beginning, what we have heard, what we have seen with our eyes, what we looked upon, and our hands touched, concerning the Word of life
1 John 5:6
This is he who came by water and blood, Jesus Christ, not by the water only, but by the water and the blood. And it is the Spirit that testifies, because the Spirit is truth.