John 21:24
This is the disciple, who testifieth of these things, and wrote these things; and we know that his testimony is true. And there are also many other things which Jesus did,
John 19:35
And he that saw, hath testified it, and his testimony is true: and he knoweth that he saith true, that ye may believe.
3 John 1:12
Demetrius hath a good testimony from all men, and from the truth itself: yea, we also bear testimony, and ye know that our testimony is true.
John 15:27
Ye also testify, because ye have been with me from the beginning.
1 John 1:1-2
That which was from the beginning, which we have heard, which we have seen with our eyes, which we have beheld, and our hands have handled of the word of life:
1 John 5:6
This is he that came by water and blood; even Jesus Christ; not by the water only, but by the water and the blood: and it is the Spirit who testifieth; because the Spirit is truth.