Incarnation of the Son of God
“Who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant, being born in the likeness of men.”
Definition
The incarnation of the Son of God is the eternal Son’s taking of a complete human nature into personal union with his divine nature, “when the fullness of time had come” (Gal. 4:4): “the Word became flesh and dwelt among us” (John 1:14) — the Son’s coming to be man, resulting in the union of two natures in the one person of Jesus Christ.
Confessional Definition
The 1689 Second London Baptist Confession states that the Son of God, “when the fullness of time was complete, did… take upon Him man’s nature, with all the essential properties and common infirmities of it, yet without sin; being conceived by the Holy Spirit in the womb of the Virgin Mary, the Holy Spirit coming down upon her: and the power of the Most High overshadowing her.”1
Biblical Basis
Paul frames the incarnation as a movement from riches to poverty for the sake of others: Christ “though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant, being born in the likeness of men” (Phil. 2:6-7). Paul describes the same act elsewhere: “when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law” (Gal. 4:4-5). John’s Gospel opens by identifying the one who “became flesh” as none other than the eternal Word who “was with God” and “was God” from the beginning (John 1:1, 14).
Objections and Responses
Doesn’t the incarnation mean that God’s own divine essence was somehow changed, mixed with, or diminished by taking on humanity? Bavinck locates the Reformed answer in a distinction between person and nature: “it was the person of the Son who became flesh. It was not the substance (the underlying reality) but the subsistence (the particular being) of the Son that assumed our nature.” Divine essence, shared fully and identically by Father, Son, and Spirit, cannot itself change or be added to; what happens in the incarnation is that the Son, a particular divine person, takes a human nature into personal union with himself, without that union touching the divine essence he shares with the Father and the Spirit. Bavinck contrasts this with the tendency in “Greek, Roman, and Lutheran theology” to speak more loosely of “the incarnation of the divine being” itself.2