Whats the most convincing way to prove what we say is true? The best argument is to ask witnesses to corroborate our claims, and the more reliable the witnesses the more convincing the argument. To defend His messianic claims, Jesus called five irrefutable witnesses: God the Father, John who spoke of Jesus as the Lamb of God, Jesus own works, the Scriptures, and Moses. Why dont people accept the witnesses? They see and hear, but their hearts are unmoved and unwilling to believe.