1 John 5:10 AMPC

[10] He who believes in the Son of God [who adheres to, trusts in, and relies on Him] has the testimony [possesses this divine attestation] within himself. He who does not believe God [in this way] has made Him out to be and represented Him as a liar, because he has not believed (put his faith in, adhered to, and relied on) the evidence (the testimony) that God has borne regarding His Son.