John 21:24
This is the disciple who testifieth of these things, and hath written these things; and we know that his testimony is true.
John 19:35
And he that hath seen hath borne witness, and his witness is true; and he knoweth that he saith what is true, that ye also may believe.
3 John 1:12
To Demetrius testimony hath been borne by all, and by the truth itself; yea, we also bear witness, and ye know that our witness is true.
John 15:27
And ye also are witnesses, because ye have been with me from the beginning.
1 John 1:1-2
That which was from the beginning, that which we have heard, that which we have seen with our eyes, that which we looked upon, and our hands handled, concerning the word of life,
1 John 5:6
This is he who came by water and blood, Jesus Christ; not in the water only, but in the water and in the blood; and the Spirit is that which beareth witness, because the Spirit is truth.