4.5 The Incarnation:
God Becomes Man
The Incarnation is the Christian belief that God became human in Jesus Christ.
The word “incarnation” comes from a Latin word meaning “in flesh.” In Christian theology, the Incarnation means that Jesus is not only a teacher, prophet, or Messiah, but that He is God’s Word made flesh.
This belief is one of the most important claims in Christianity.
Christians believe that in Jesus, God entered human life in a personal and visible way. Jesus lived a full human experience including birth, hunger, grief, temptation, suffering, and death. At the same time, Christians believe He fully and perfectly revealed God’s character, authority, mercy, truth, and salvation.
How This Doctrine Developed
The earliest followers of Jesus were Jewish. They believed in one God: the God of Israel. They did not yet have the later philosophical Trinitarian language about “natures” and “persons.”
Their experience of Jesus began with His teaching, authority, miracles, death, the belief that God raised Him from the dead, and their hopes of the Jewish Messiah.
Over time, Christians tried to explain how Jesus could be truly human and yet uniquely divine.
Some early groups emphasized Jesus’ humanity so strongly that they saw Him mainly as a man chosen or empowered by God. For example, some Jewish-Christian groups, such as the Ebionites, viewed Jesus as a human Messiah rather than as fully God. Other views, sometimes called Adoptionism, taught that Jesus was a man specially adopted or exalted by God.
Other groups emphasized Jesus’ divinity so strongly that His humanity seemed less real. Docetism taught that Jesus only appeared to be human and only appeared to suffer. Some Gnostic-influenced views also struggled with the idea that God would truly take on physical flesh.
These debates led early Christians to define the doctrine of the Incarnation more carefully.
In AD 325, the Council of Nicaea affirmed that the Son (Jesus) is not a created being, but shares in the divine nature of God.
In AD 451, the Council of Chalcedon taught that Jesus is one person in two natures: fully God and fully human.
These councils tried to explain and protect what they believed the early Christian writings and traditions already taught about Him.
The Word Became Flesh
One of the clearest biblical passages connected to the Incarnation is found in the Gospel of John where Jesus is described as “the Word.” In Greek, this word is Logos.
John 1:1-5 ESV:
[1] In the beginning was the Word, and the Word was with God, and the Word was God.
[2] He was in the beginning with God.
[3] All things were made through Him, and without Him was not any thing made that was made.
[4] In Him was life, and the life was the light of men.
[5] The light shines in the darkness, and the darkness has not overcome it.
These verses in John 1 present Jesus as the Word through whom God creates and reveals Himself. John says that all things were made through Him, that life was in Him, and that the Word became flesh.
These verses also draw on the Genesis theme that God creates by speaking. In Genesis, God says, “Let there be light,” and there is light. In the Gospel of John, Jesus is presented as God’s Word through whom creation, life, and light come.
When John says, “In the beginning was the Word,” he is connecting Jesus to God’s creative Word from the beginning of the world.
The Incarnation became one of the most important foundations for Christian belief about Jesus. Christians came to believe that Jesus was not simply sent by God in the way a prophet is sent by God. They believed that God’s own Word, wisdom, and self-expression became human in Him.
Christians therefore say that Jesus reveals God. In Christianity, knowing Jesus means more than knowing facts about Him. It means recognizing God’s character in Him and responding with trust, repentance, and obedience.
Jesus as Son of God
Christians call Jesus the Son of God.
In the Bible, “son of God” can have more than one meaning. Israel is sometimes described as God’s son. Kings could be described as God’s son. The Messiah could be understood as God’s son in a royal or chosen sense.
Christianity takes the title further. In mainstream Christian belief, Jesus shares in God’s own divine identity.
Christians do not believe God had a biological son. The title “Son of God” is theological, not physical. It describes Jesus’ unique relationship with God and His role as the one who reveals God to the world.
Fully Human
The Incarnation teaches that Jesus was fully human.
He was born as a child. He grew up in a family. He lived in a real time and place. He experienced hunger, tiredness, sorrow, pain, temptation, and death.
Christianity does not teach that Jesus only appeared to be human. He truly entered human life.
Because Jesus was fully human, Christians believe He can represent human beings before God, sympathize with human weakness, and show what faithful human life under God’s rule looks like.
His humanity is also important because Christianity teaches that salvation is not God rescuing people from a distance. In Jesus, God enters into human suffering, weakness, and death.
Fully Divine
The Incarnation also teaches that while Jesus was fully human, He was also fully divine.
Christians believe that Jesus reveals God in a way no ordinary prophet or teacher could. The Gospels show Jesus forgiving sins, speaking with authority, receiving worship, calming storms, healing the sick, raising the dead, and identifying Himself closely with God’s work.
The New Testament presents Jesus as uniquely connected to God’s presence, authority, and salvation.
Therefore, mainstream Christianity eventually taught that Jesus is both fully human and fully divine.
He is not half-God and half-man. He is not a human body with God replacing a human soul. He is not merely a very holy man inspired by God. He is one person with both a fully human nature and a fully divine nature.
Why Christians Believe God Became Man
Christians believe that human beings are deeply affected by sin and that sin separates people from God. Because humanity needs rescue, healing, forgiveness, and transformation, Christians believe the Incarnation was necessary.
In Jesus, Christians believe God reveals His character, calls people to repentance, shows what true human life looks like, defeats sin and death, and opens the way for people to be reconciled to God.
The Incarnation is about God entering the human condition in order to heal and restore it.
Why the Incarnation Matters
The Incarnation shapes how Christians understand Jesus, God, and salvation.
If Jesus is only a teacher, then Christianity is mainly about following His teachings.
If Jesus is only a prophet, then Christianity is mainly about listening to the message God gave Him.
But if Jesus is God’s Word made flesh, then Christianity is centered not only on what Jesus taught, but on who Jesus is.
For Christians, Jesus does not only speak for God. He reveals God.
He does not only teach people how to live. He also shows what a life fully submitted to God looks like.
He does not only announce salvation. He is central to salvation itself.
Next, in section 4.6 we will look at Jesus’ death and the cross.