This is He who came by water and blood--Jesus Christ; not only by water, but by water and blood. And it is the Spirit who bears witness, because the Spirit is truth.
1 John 5:6
Surrounding context
5:5 Who is he who overcomes the world, but he who believes that Jesus is the Son of God?
5:6 This is He who came by water and blood--Jesus Christ; not only by water, but by water and blood. And it is the Spirit who bears witness, because the Spirit is truth.
5:7 For there are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one.