John 3:32-33
3:32 He testifies about what he has seen and heard, but no one accepts his testimony.
3:33 The one who has accepted his testimony has confirmed clearly that God is truthful.
John 5:34
5:34 (I do not accept human testimony, but I say this so that you may be saved.)
John 8:13
8:13 So the Pharisees objected, “You testify about yourself; your testimony is not true!”
John 8:17
8:17 It is written in your law that the testimony of two men is true.