'Testimony is True' in the Bible

Jesus answered, "Even if I bear witness of myself, my testimony is true, for I know where I came from and where I am going; but you do not know where I come from and where I am going.

He who saw it has testified, and his testimony is true, and he knows that he tells the truth, that you also may believe.

This is the disciple who testifies to these things, and who wrote these things; and we know that his testimony is true.

This testimony is true. Therefore, rebuke them sharply, so that they may be sound in the faith

Demetrius has received a good testimony from everyone, and from the truth itself; and we add our testimony, and you know that our testimony is true.