'Testimony' in the Bible

If we accept the testimony of men, the testimony of God is greater, because this is the testimony of God that he has testified concerning his Son.

(The one who believes in the Son of God has the testimony in himself; the one who does not believe God has made him a liar, because he has not believed in the testimony that God has testified concerning his Son.)

And this is the testimony: God has given us eternal life, and this life is in his Son.