Incarnation is a term used by theologians to indicate that Jesus, the Son of God, took on human flesh. This is similar to the hypostatic union. The difference is that the hypostatic union explains how Jesus’ two natures are joined, and the Incarnation more specifically affirms His humanity.
The word incarnation means “the act of being made flesh.” It comes from the Latin version of John 1:14, which in English reads, “The Word became flesh and made His dwelling among us.” Because of the near-exclusive use of the Latin Vulgate in the church through the Middle Ages, the Latin term became standard.
Biblical support for Jesus’ humanity is extensive. The Gospels report Jesus’ human needs including sleep (Luke 8:23), food (Matthew 4:2; 21:18), and physical protection (Matthew 2:13-15; John 10:39). Other indications of His humanity are that He perspired (Luke 22:43-44) and bled (John 19:34). Jesus also expressed emotions including joy (John 15:11), sorrow (Matthew 26:37), and anger (Mark 3:5). During His life, Jesus referred to Himself as a man (John 8:40), and after His resurrection His humanity was still recognized (Acts 2:22).
But the purpose of the Incarnation was not to taste food or to feel sorrow. The Son of God came in the flesh in order to be the Savior of mankind. First, it was necessary to be born “under the law” (Galatians 4:4). All of us have failed to fulfill God’s Law. Christ came in the flesh, under the Law, to fulfill the Law on our behalf (Matthew 5:17; Galatians 4:5).
Second, it was necessary for the Savior to shed His blood for the forgiveness of sins (Hebrews 9:22). A blood sacrifice, of course, requires a body of flesh and blood. And this was God’s plan for the Incarnation: “When Christ came into the world, he said: ‘Sacrifice and offering [under the Old Covenant] you did not desire, but a body you prepared for me’” (Hebrews 10:5). Without the Incarnation, Christ could not really die, and the cross is meaningless.
God did an incredible work in sending His only begotten Son into the world and providing us with a salvation we do not deserve. Praise the Lord for that moment in which “the Word became flesh.” We are now redeemed “with the precious blood of Christ, a lamb without blemish or defect” (1 Peter 1:19).
Jesus was both human and divine. Please read about the divinity of Jesus here.