Third, Jesus is God and man “in two entire and distinct natures, and one person, forever” (WLC 36; see Heb. 7:24–25). Jesus is a divine person, not a human person. The second person of the Trinity became a human being, but He did not become a human person. The humanity of Christ is the humanity of the Son of God, the human nature being united to the divine in one person. Christ’s two natures do not mix to create one person. The person of the Son became man and the man Christ Jesus ever lives to make intercession for His people (v. 25). Jesus remained the form of God while He took on the form of a servant, so that all should confess that Jesus is Lord, to the glory of God the Father (Phil. 2:5–11).
Do we testify that Jesus is the Christ, the Son of the living God (Matt. 16:16)? Do we confess that He is God the Son come in the flesh?
How Did the Mediator of the Covenant of Grace Become Man?
Christ the Son of God became man, by taking to himself a true body, and a reasonable soul, being conceived by the power of the Holy Ghost in the womb of the virgin Mary, of her substance, and born of her, yet without sin (WLC 37).
How did the Son of God become man? He did not do so by subtracting from His divine nature, but by adding a human nature. He took “to himself a true body and a reasonable soul” (Westminster Shorter Catechism 22; see Heb. 2:14–17). He did not pretend to take a human body. Nor did He take a human body without a human soul. Just as the separation of body and spirit constitutes human death (James 2:26), so Jesus gave up His spirit when He died (John 19:30). His divine nature did not replace His human soul. He took on true human nature, including everything that it meant for Him to be human.
Jesus was also “conceived by the power of the Holy Ghost” (WSC 22; see Luke 1:27, 31, 35; Gal. 4:4). While He had no human father, the Spirit conceived Him “in the womb of the Virgin Mary.” He was born “of her substance,” just as every human baby is nurtured in the womb and born of the substance of its mother (Westminster Confession of Faith 8.2). Yet since He was the Son of God, Mary became the mother of God because she bore God in human flesh. We should not worship Mary or pray to her. Instead, we should believe in her Son like she did (Luke 1:47). Jesus became the Seed of the Woman (Gen. 3:15) without inheriting Adam’s original sin. Again, He was truly like us in every way, “yet without sin” (Rom. 8:3; Heb. 4:15).
Do you testify to Jesus as a true historical human person? “By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God” (1 John 4:2–3).
Why Did the Mediator of the Covenant of Grace Have to Be God?
It was requisite that the Mediator should be God, that he might sustain and keep the human nature from sinking under the infinite wrath of God, and the power of death; give worth and efficacy to his sufferings, obedience, and intercession; and to satisfy God’s justice, procure his favor, purchase a peculiar people, give his Spirit to them, conquer all their enemies, and bring them to everlasting salvation (WLC 38).
It is one thing to know who Jesus is. It is another thing to know why He has to be who He is in order to save us. The catechism gives three reasons why He had to be God.
First, His divine nature sustained and kept “his human nature from sinking under God’s wrath and the power of death.” The eternal Son is an infinitely glorious person. God’s wrath is equally infinite and eternal. Mere human beings cannot bear the infinite wrath of God, which is why hell is eternal for them. While Christ suffered in His human nature, the divine nature sustained Him in His sufferings. This was why “Christ also suffered once for sins, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the Spirit” (1 Peter 3:18). Peter also argued that it was impossible for death to hold Him (Acts 2:24–25). While a sinful man could die and not rise, death could not hold the righteous God-man when He died.
Second, Christ’s deity gave “worth and efficacy to his obedience, sufferings, and intercession” (WLC 38). God is not under the law, and He is not subject to obeying the law. The law reflects God’s character and will. Yet God sent His Son to be born of a woman so that He might be born under the law (Gal. 4:4) and to obey it to the point of death (Phil. 2:8). Scripture asks us, if a man sins against God, then who can intercede for Him (1 Sam. 2:25)? Yet, the eternal Son alone measures up to the character and matches the worth and glory of His Father. As the second Adam, Christ by His obedience made many righteous (Rom. 5:19). The blood He shed was the blood of God (Acts 20:28) because His humanity was the humanity of the Son of God. As man He prays for His people (John 17), but as the God-man He always prays according to His Father’s will and His intercession is always effective.