1. The person or active subject of the incarnation is the eternal Son.
John 1:14 is clear: “The Word became flesh.” In other words, it was the Son from eternity who became incarnate, not the divine nature. The Son, who is in eternal relation to the Father and Spirit, willingly humbled himself and chose to assume a human nature in obedience to his Father and for our salvation (Phil. 2:6-8).
2. As the eternal Son, the second person of the triune Godhead, he is the full image and expression of the Father and is thus fully God.
Along with the Father and Spirit, the Son fully and equally shares the divine nature. As the image and exact correspondence of the Father (Col. 1:15; Heb. 1:3), the Son is fully God. All of God’s perfections and attributes are his since Christ is God the Son (Col. 2:9). As the Son, he participates in the divine rule, receives divine worship, and does all divine works as the Son (Ps. 110:1; Eph. 1:22; Phil. 2:9-11; Col. 1:15-17; Heb. 1:2-3; Rev. 5:11-12).
3. As God the Son, he has always existed in an eternally-ordered relation to the Father and Spirit, which now is gloriously displayed in the incarnation.
It was fitting that the Son alone, who is from the Father by the Spirit, became incarnate and not the other divine persons (John 1:1-2, 14, 18). In the incarnation, the Son displayed his divine-filial dependence on the Father and always acted in relation to the Father by the Spirit (John 5:19-30; Mark 1:12; Luke 4:1-21). From eternity and in the incarnation, the Son never acted on his own or independently but always in relation to and inseparably from his Father and the Spirit.
4. The incarnation is an act of addition, not subtraction.
In the incarnation, the eternal Son who has always possessed the divine nature has not changed or set aside his deity. Instead, he has added to himself a second nature, namely a human nature consisting of a human body and soul (Phil. 2:6-8). As a result, the individual Jesus is one person—the Son—who now subsists in two natures, and thus is fully God and fully man.
5. The human nature assumed by the divine Son is fully human and completely sinless.
Christ’s human nature was unfallen and untainted by the effects of sin. Our inborn inclination to anti-God rebellion was not part of Jesus’s human makeup. Jesus fully experienced the effects of living in a fallen world, but he did not share the guilt or disposition of Adam’s sin passed on to the human race. In fact, Jesus never committed a sin, nor could he (Matt. 3:15; John. 8:46; Heb. 4:15; 7:26; 1 Pet. 1:19). Although he was tempted like us, he perfectly obeyed his Father, even unto death, as our covenant mediator, thus accomplishing our salvation as the man Christ Jesus (1 Tim. 2:5; Heb. 5:5-10).
6. The virgin conception was the glorious means by which the incarnation took place.
The incarnation was thoroughly supernatural and a demonstration of our triune God’s sovereign and gracious initiative to redeem his people (Matt. 1:18-25; Luke 1:26-38). The virgin conception was the time and means by which the divine Son added to himself a human nature. By the virgin conception, the triune God created a new human nature for the Son, and as a result of this action, in Jesus, we truly meet God face-to-face, not indwelling or overshadowing human flesh but in full undiminished glory. Although we behold Jesus as a man, he is much more; he is the Lord, the divine Son who humbles himself and veils his glory by becoming one with us.
7. From conception, the Son limited his divine life in such a way that he did not override the limitations of his human nature.
As a result of the incarnation, the divine Son lives as a true man with the normal physical, mental, volitional, and psychological attributes and capacities of original humanity. As the incarnate Son, he experienced the wonder and weaknesses of a completely human life. He grew in wisdom and physical stature (Luke 2:52), experienced tears and joy, and suffered death and a glorious resurrection for his people and their salvation (John 11:33, 35; 19:30; 1 Cor. 15:3-4).
8. But the Son was not limited to his human nature alone since he continued to act in and through his divine nature.
This truth is best demonstrated in the incarnate Son’s continuing to sustain the universe (Col. 1:16-17; Heb. 1:3), alongside Christ’s other divine actions during his life and ministry. In Christ, there are two natures which remain distinct and retain their own attributes and integrity, yet the Son is able to act through both natures. For this reason, the Son is not completely circumscribed by his human nature; he is also able to act outside of it in his divine nature.
When and how the Son acts through both natures is best explained in terms of Trinitarian relations worked out in redemptive history for the sake of our salvation. The Son, who has always inseparably acted from the Father and by the Spirit, continues to do so but now as the obedient Son acting as our covenant representative and substitute. In the incarnation, neither the Son’s deity nor his humanity is diminished.
9. By taking on our human nature, the Son became the first man of the new creation, our great mediator and new covenant head.
As the Son incarnate, our Lord Jesus Christ in his life, death, and resurrection, reverses the work of the first Adam and forges ahead as the last Adam, our great trailblazer and champion (Heb. 2:10). As a result of the incarnation, God the Son becomes perfectly qualified to meet our every need, especially our need for the forgiveness of our sin (Heb. 2:5-18; 7:22-28; 9:15-10:18).
10. God the Son incarnate is utterly unique and alone Lord and Savior.
Jesus is in a category all by himself. Given who God is in all of his glory and moral perfection, and what sin is before God, apart from the Son’s incarnation and his entire work for us, there is no salvation (John 14:6; Acts 4:11). As the divine Son, he alone satisfies God’s own judgment against us and the demand for perfect obedience (Rom. 5:12-21). As the incarnate Son, he alone can identify with us as our representative and substitute (Heb. 5:1). Our salvation hope for the payment of our sin and our full restoration as God’s image-bearers is only accomplished in Jesus Christ our Lord (Rom. 3:21-26; Heb. 2:5-18).