When Jesus calls himself “God’s only-begotten Son” and Peter and others bear witness to this, the expression means that of all men only Jesus is more than a man. [441-445, 454]
In many passages of the New Testament Jesus is called “Son”. At his baptism and his transfiguration, the voice from heaven calls Jesus “my beloved Son”. Jesus discloses to his disciples his unique relationship to his heavenly Father. “All things have been delivered to me by my Father; and no one knows the Son except the Father, and no one knows the Father except the Son and any one to whom the Son chooses to reveal him” (Mt 11:27). The fact that Jesus Christ really is God’s Son comes to light at the Resurrection.