He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.
Hath the witness - of God; which х Theou (G2316)] A, Vulgate, have; but 'Aleph (') B omit; by His Spirit (1 John 5:8).
In himself - God's Spirit dwelling in him; witnessing that "Jesus is the Lord" (1 Corinthians 12:3), "the Christ," "the Son of God" (1 John 5:1; 1 John 5:5). The Spirit's witness in the believer himself to his Sonship is not expressed, but follows from his believing the witness of God to Jesus' divine Sonship.
Believeth not God, х pisteuoon (G4100) too (G3588) Theoo (G2316)] - credits not His witness. So B 'Aleph ('); but Lambda, Vulgate х huioo (G5207)], 'the Son.'
Made him a liar - a consequence which virtual and even avowed unbelievers may well startle back from as fearful blasphemy (1 John 1:10).
Believeth not the record, х eis (G1519) teen (G3588) marturian (G3141)] - 'IN the witness.' Refusal to credit God's testimony is involved in refusing to believe IN (to rest one's trust in) Jesus Christ (1 John 5:10) х eis (G1519) ton (G3588) huion (G5207)], the object of it. 'Divine faith is an assent to something as credible upon God's testimony. This is the highest faith; because the object hath the highest credibility, because grounded upon God's testimony, which is infallible' (Pearson 'On Creed').
Gave - `hath testified, and now testifies.'
Of - concerning.