'Testimony' in the Bible

Jesus Christ is He who came with water and blood; not with the water only, but with the water and with the blood. And it is the Spirit who gives testimony-- because the Spirit is the Truth.

For there are three that give testimony-- the Spirit, the water, and the blood;

If we accept the testimony of men, God's testimony is greater: for God's testimony consists of the things which He has testified about His Son.

He who believes in the Son of God has the testimony in his own heart: he who does not believe God has made Him a liar, in that he has refused to accept the testimony which God has given about His Son.

And that testimony is to the effect that God has given us the Life of the Ages, and that this Life is in His Son.