In Context

5 Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?

6 This is he that came by water and blood, Jesus Christ: not by water only, but by water and blood. And it is the Spirit which testifieth, that Christ is the truth.

7 And there are three who give testimony in heaven, the Father, the Word, and the Holy Ghost. And these three are one.

8 And there are three that give testimony on earth: the spirit, and the water, and the blood: and these three are one.

9 If we receive the testimony of men, the testimony of God is greater. For this is the testimony of God, which is greater, because he hath testified of his Son.

10 He that believeth in the Son of God, hath the testimony of God in himself. He that believeth not the Son, maketh him a liar: because he believeth not in the testimony which God hath testified of his Son.

1 John 5:8 in Other Translations