"No one has seen God at any time. The only begotten Son, who is in the bosom of the Father, He has declared Him" (John 1:18).
The glory of “grace and truth” not revealed in John the Baptist but in the “only begotten”—Jesus Christ. This extraordinary statement of John’s concerning the Son’s relationship to the Father has caused great controversy in the church.
Some have interpreted “only begotten” as “being born,” which implies that Christ had a beginning. But this is not John’s emphasis in this passage. “Only begotten” refers to the eternal generation of the Son in the Trinity, not as an emanation of a different substance than God, but as God Himself. This “Trinitarian Sonship” expresses the eternality of the Son and His intimate relation to the Father. Christ, in other words, did not become God’s Son when He was born to Mary, but He had been God’s own Son from all eternity: “And now, O Father, glorify Me together with Yourself, with the glory which I had with You before the world was” (John 17:5).
Because of this Sonship, the religious leaders crucified Christ. He claimed to be Yahweh, and such a claim was in violation of everything the Jewish religious establishment believed in. They could not accept Jesus’ claim that He was the eternal Son of God, begotten of the Father.
The glory of Christ as the “begotten God,” who proceeds from the Father for all eternity, possesses a fullness of grace and truth that exceeds the law given to Moses. Hendriksen comments, “There was nothing wrong with the law, moral and ceremonial. It had been given by God through Moses. It was preparatory in character. It revealed man’s lost condition and it also foreshadowed his deliverance. But there were two things which the law as such did not supply: grace so that transgressors could be pardoned and helped in time of need, and truth, i.e., the reality to which all the types pointed (think of the sacrifices). Christ, by His atoning work, furnished both. He merited grace and He fulfilled the types.”
Though the law was given, grace and truth came through Christ, who is called in this passage by His full name for the first time in this gospel. In the fullness of the person of Jesus Christ, as the God-man, only begotten of the Father, we have unmerited favor with God and the fulfillment of Old Testament law.
Read Luke 22:63–23:5. What did the Sanhedrin ask Jesus (v. 70)? Their use of “Son of God” has direct reference to deity. What was Jesus’ response? What is the significance of His saying “I AM”? (See Ex. 3:14.) When someone says to you that Jesus was not God, how can you answer them?