This is the one who came by water and blood: Jesus Christ. He did not come by water only, but by water and blood. And it is the Spirit who testifies, because the Spirit is the truth.
In context
4For everyone who has been born of God overcomes the world. And this is the victory that has overcome the world: our faith. 5Who is it that overcomes the world, but the one who believes that Jesus is the Son of God? 6This is the one who came by water and blood: Jesus Christ. He did not come by water only, but by water and blood. And it is the Spirit who testifies, because the Spirit is the truth. 7For there are three that testify in heaven: the Father, the Word, and the Holy Spirit; and these three are one. 8And there are three that testify: the Spirit, the water, and the blood; and these three agree as one.
