If Jesus has a human nature, and if change is proper to humanity rather than divinity, then we can attribute change to Jesus’s person according to his human nature. Since Christ’s humanity has no identity or existence apart from the eternal Son uniting it to himself, we attribute the “becoming” of his humanity to the personal subject of the incarnation, the divine Son. So, the divine Son “becomes” not in his divine nature, but according to the coming-into-existence of his human nature. One might push back since John emphasizes the Word’s becoming, not the flesh’s coming-into-existence. But recall that what is new in John 1:14 is not the Word’s existence, for he eternally existed “in the beginning” (John 1:1). What is new is the Son’s flesh, which is distinct from his divinity. The emphasis on the Word or divine Son in John 1:14 is fitting because the humanity of Jesus exists only in relation to the Son.
While Christmas brings tidings of comfort and joy, it also provides one of the most puzzling questions in the Christian faith. The question centers on a simple yet stunning confession in the Gospel of John: “The Word was God. . . . And the Word became flesh” (John 1:1, 14). The term theologians use to describe this miraculous event is incarnation — God the Son became man.
Much about the incarnation bewilders, but perhaps the greatest mystery relates to one word in John 1:14 — became. What does it mean that the Word became? Initially, it seems that God changed. But the Bible says God is unchangeable, or immutable. God declares, “I the Lord do not change” (Malachi 3:6). The psalmist says of God, “You are the same, and your years have no end” (Psalm 102:27). James says that in God “there is no variation or shadow due to change” (James 1:17). How does this fit with John 1:14, “the Word became flesh”?
The incarnation is mysterious, and to deny or ignore its mystery displays some form of hubris. Honest attempts to describe the incarnation will fall short. Nonetheless, God really reveals his ways to us in Scripture. Because God is one, his written word is organically unified. Therefore, we can ask, What must this specific passage mean if everything in Scripture is true? What all of Scripture says about Christ supplies us with concepts and categories that help us interpret John 1:14. We can summarize these concepts and categories in a short sentence: Jesus is one person with two natures.
Jesus has two natures: divine and human. We do not need to venture far from John 1:14 to see this, but a short overview of other passages will help.
Jesus is fully God. Harking back to Exodus 3:14, Jesus applies the divine name to himself, saying, “Before Abraham was, I am” (John 8:58). Paul writes, “To [the Israelites] belong the patriarchs, and from their race, according to the flesh, is the Christ, who is God over all” (Romans 9:5). Also a plethora of other texts show Jesus as God (for example, Philippians 2:6; Titus 2:13; 2 Peter 1:1; 1 John 5:20; Hebrews 1:3, 8; Psalm 45:6–7). Additionally, the Bible attributes acts to Jesus that only God performs, like creating (John 1:3), sustaining (Hebrews 1:3), forgiving sins (Mark 2:7), and more. Every attribute belonging to God also belongs to Jesus, because he is God.
Jesus is also fully man. Jesus is “the son of David, the son of Abraham” (Matthew 1:1). Paul says that Jesus “descended from David according to the flesh” (Romans 1:3), that he was “born of woman” (Galatians 4:4), and that he was “born in the likeness of men” (Philippians 2:6–7; also Romans 8:3). Jesus has bones, flesh, and body parts, unlike a spirit (Luke 24:39–43). He “suffered in the flesh” (1 Peter 4:1). He thirsted (John 19:28), ate and drank (Luke 5:30), and slept (Mark 4:38). Thus, the author of Hebrews writes, “He had to be made like his brothers in every respect” (Hebrews 2:17). Every attribute belonging to man belongs to Jesus, except sin (Hebrews 4:15), for he is truly man.
Christ’s two natures are distinct, yet inseparable. In other words, Christ’s two natures are not mixed together to form a third nature, but at the same time, they exist inseparably in the one person of Christ. The Creed of Chalcedon therefore says that Jesus is
to be acknowledged in two natures,
inconfusedly, unchangeably, indivisibly, inseparably;
the distinction of natures
being by no means taken away by the union,
but rather the property of each nature being preserved.
Both divine and human qualities are attributed to Christ, because he has both divine and human natures.