In Context

5 who is he who is overcoming the world, if not he who is believing that Jesus is the Son of God?

6 This one is he who did come through water and blood — Jesus the Christ, not in the water only, but in the water and the blood; and the Spirit it is that is testifying, because the Spirit is the truth,

7 because three are who are testifying in the heaven, the Father, the Word, and the Holy Spirit, and these — the three — are one;

8 and three are who are testifying in the earth, the Spirit, and the water, and the blood, and the three are into the one.

9 If the testimony of men we receive, the testimony of God is greater, because this is the testimony of God that He hath testified concerning His Son.

10 He who is believing in the Son of God, hath the testimony in himself; he who is not believing God, a liar hath made Him, because he hath not believed in the testimony that God hath testified concerning His Son;

1 John 5:8 in Other Translations