Son of God

The OT establishes Sonship in three voices that converge in the Messiah. First, Psalm 2:7 — "Thou art my Son; this day have I begotten thee" — addressed to the anointed king on Zion. Calvin, commenting on Psalm 2, reads the verse as immediately of David but ultimately of Christ, since the everlasting reign promised in Ps 2:8–12 cannot be settled on any merely human king. Second, 2 Samuel 7:14 — God's covenant with David: "I will be his father, and he shall be my son." Matthew Henry hears in this language a doubled register: an immediate covenant with Solomon, and beyond him, the Son whose throne would never be cast down. Third, the Sonship is hinted in places where the OT itself slows down before a mystery — Proverbs 30:4: "Who hath ascended up into heaven, or descended? what is his name, and what is his son's name, if thou canst tell?" Henry treats Agur's question as a Sonship hint deliberately left in the canon to be answered at the Father's voice from heaven over the Jordan.

The Father's voice opens Jesus's public ministry — "This is my beloved Son, in whom I am well pleased" (Matt 3:17) — and the same voice repeats at the Transfiguration (Matt 17:5). Peter's confession at Caesarea Philippi joins the Christ and Son titles into one breath: "Thou art the Christ, the Son of the living God" (Matt 16:16), and Mark opens his gospel with both — "the gospel of Jesus Christ, the Son of God" (Mk 1:1). John makes the title programmatic: "these are written, that ye might believe that Jesus is the Christ, the Son of God" (Jn 20:31). Athanasius, writing against Arian denial, anchors the eternal Sonship in Heb 1:5 and Ps 2:7 read together — the begotten language is not sequential but eternal generation, the Son's relation to the Father always-already in being. Calvin, treating Hebrews 1, hears the Son's superiority to angels not as honorific but as a structural claim about the unique mediator. Paul caps it at Rom 1:4: declared the Son of God "with power, according to the spirit of holiness, by the resurrection from the dead."

Athanasius's On the Incarnation makes the Son's Sonship non-negotiable for soteriology: only the eternal Son could become flesh in a way that joins the divine and the human without confusion, and only such a union accomplishes the salvation of the human race. Calvin treats the Son's relation to the Father as the ground of Christian adoption — believers do not become sons in the unique sense Christ is, but become sons by union with the Son who is. Henry adds the pastoral note: every believer's prayer travels along the Son's relation to the Father, not parallel to it but inside it (cf. Rom 8:15–17). The title is therefore not honorific but constitutional: the church's confession that Jesus is the Son of God is the line on which Trinitarian theology, the doctrine of adoption, and the structure of Christian prayer all hang. As 1 John 4:15 puts it, the confession itself is what marks indwelling: "Whosoever shall confess that Jesus is the Son of God, God dwelleth in him."