'Valid' in the Bible

“If I alone testify about Myself, My testimony is not valid.

There is another [My Father] who testifies about Me, and I know [without any doubt] that His testimony on My behalf is true and valid.

Then the Pharisees told Him, “You are testifying on Your own behalf; Your testimony is not valid.”

Jesus replied, “Even if I do testify on My own behalf, My testimony is valid, because I know where I came from and where I am going; but you do not know where I come from or where I am going.

Even in your own law it is written that the testimony of two persons is true [valid and admissible].