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;
10
Whoever believes in the Son of God accepts this testimony. Whoever does not believe God has made him out to be a liar, because they have not believed the testimony God has given about his Son.
Young's Literal Translation is in the public domain.