John 21:24
This is the disciple who testifies to these things and who wrote them down, and we know that his testimony is true.
John 19:35
The man who saw it has testified to it -- and his testimony is true, and he knows that he is telling the truth -- in order that you too may come to believe it.
3 John 1:12
Demetrius has a good testimony from everybody and from truth itself; yea, from me too, and you know that my testimony to him is true.
John 15:27
And you too are to bear testimony to me, because you have been with me from the start."
1 John 1:1-2
It is what existed from the beginning, what we have heard, what we have seen with our own eyes, what we have beheld, what our own hands have touched, about the very message of life --
1 John 5:6
He is the One who came through water and blood -- Jesus Christ; not through water only but through water and blood. The Spirit also testifies to this, because the Spirit is truth.