1 John 5:1, 6-8

Whosoever believeth that Jesus is the Christ is begotten of God: and whosoever loveth him that begat loveth him also that is begotten of him.

This is he that came by water and blood, even Jesus Christ; not with the water only, but with the water and with the blood. And it is the Spirit that beareth witness, because the Spirit is the truth. For there are three who bear witness, the Spirit, and the water, and the blood: and the three agree in one.