NET

10 (The one who believes in the Son of God has the testimony in himself; the one who does not believe God has made him a liar, because he has not believed in the testimony that God has testified concerning his Son.)

Darby

10 He that believes on the Son of God has the witness in himself; he that does not believe God has made him a liar, because he has not believed in the witness which God has witnessed concerning his Son.

KJV

10 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.