The fact that Jesus is true God is explained under The Trinity. He is the Son of God, one of the persons of the Trinity, because that is what God’s Word teaches us about him. This section will cover how we know that Jesus is also a true human being. It will also talk about why the Savior had to be both true God and a true human being.
Jesus is Fully Human
There are some people who claim that the human being Jesus never existed. There are also some who claim that Jesus only existed spiritually and simply appeared to exist physically. Not only does world history disagree, but the Word of God also disagrees. First of all, Jesus had a real human birth (Matthew 1:18-2:23; Luke 1:26-56, 2:1-40). Secondly, Jesus grew up in the normal human way: “The child grew and became strong; he was filled with wisdom, and the grace of God was upon him” (Luke 2:40). We aren’t told much about his childhood, but the Gospel of Luke does include an account about him when he was 12 years old (Luke 2:41-51). And from there, he continued to grow into an adult: “Jesus grew in wisdom and stature, and in favor with God and men” (Luke 2:52). Jesus was born fully human and grew up fully human.
“When the time had fully come, God sent his Son, born of a woman, born under law, to redeem those under law.”
There’s plenty of other evidence in the Bible that shows Jesus is fully human. The most obvious is when someone calls Jesus a human (e.g., Mark 15:39; John 19:5; Acts 2:22; Romans 5:15-19). We also hear about Jesus facing basic human needs. He hungered (Matthew 4:2), he thirsted (John 19:28), and, even more basic, he breathed (Luke 23:46). All human beings are made up of body and soul (the soul is also called a “spirit” in the Bible). Jesus had a body (e.g., Luke 24:39-43; John 1:14; Acts 2:31) and a soul (Matthew 26:38; Luke 23:46; John 19:30). All humans come from other humans (have ancestors). Jesus had ancestors, too (Matthew 1:1-17; Luke 3:23-38). In fact, that was the whole reason God chose the Israelites to be his people. God made them his people so that they could biologically bring forth the promised Savior into the world while preserving the message of the promise (see Forgiveness of Sins for All People).
Another reason we know Jesus was a real human being was that he physically died. In order for a human body to physically die, it needs to be physically alive. His death was not a result of sin like the rest of us because he didn’t have any sin. He died because he chose to die—for us. He said this about his life, “No one takes it from me, but I lay it down of my own accord. I have authority to lay it down and authority to take it up again” (John 10:18). Jesus physically became a part of this world, and he physically died as a part of this world.
Why Fully Human?
That’s also why he became a true human being: to die in our place and pay for our sins. Human beings are under God’s law. And since God is just, he has to punish people for all the times they break his law. But if the Savior was going to come and live a perfect life for us and be punished for sin in our place (as mentioned in Forgiveness of Sins for All People), he needed to be under God’s law. This means he needed to be human. As Paul tells us, “When the time had fully come, God sent his Son, born of a woman, born under law, to redeem those under law” (Galatians 4:4-5). To redeem something is to buy it back, as in the case of buying someone out of slavery (the act of redeeming is called redemption). In order for Jesus to redeem the world from the punishment of breaking God’s law, he needed to become part of the world and be under God’s law (Hebrews 2:14-17). Jesus had to be a true human being.
Human, Yet Without Sin
“God was pleased to have all his fullness dwell in him, and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross.”
But if all human beings are born sinful (as discussed in sections Sin and Repentance and “Justified” by Grace through Faith), how could Jesus be a true human being and also be without sin? Jesus was not conceived by a human father. He was conceived by the Holy Spirit and, as impossible as it sounds, a virgin human mother. When an angel first told his mother, Mary, what was going to happen, even she didn’t understand how it was possible. “‘How will this be,’ Mary asked the angel, ‘since I am a virgin?’ The angel answered, ‘The Holy Spirit will come upon you, and the power of the Most High will overshadow you. So the holy one to be born will be called the Son of God’” (Luke 1:34-35). This means Jesus, born of a virgin woman and through the power of the Holy Spirit, was born without a sinful nature. He also carried out God’s Law perfectly. He was completely righteous and without sin, just as the Savior needed to be.
Why True God?
If the Savior was a true human and lived a perfect life, why did he also have to be true God? He had to be true God in order for his perfect life and his death to be given in place of all people. “No man can redeem the life of another” (Psalm 49:7—see also verse 15). If the Savior was only a human, then living a perfect life would have only meant eternal life for himself. But because Jesus was God, his righteous life was able to cover the unrighteous lives of all people, and his suffering was able to pay for the punishment of the sins of all people. As the apostle Peter says, “It was not with perishable things such as silver or gold that you were redeemed from the empty way of life handed down to you from your forefathers, but with the precious blood of Christ” (1 Peter 1:18-19). Christ’s blood was able to pay for the sins of the whole world because it wasn’t just the blood of a normal human being—it was the precious blood of a man who was also true God.
This whole teaching means that God saw our hopeless situation as humans plagued by sin and death, so he himself became a human to fix it all. The Son of God became a human being to fulfill God’s law for us and to suffer the consequences of the sin we committed. And he did it all because of the love he has for us. Jesus Christ, our Savior, was true God and true human being because he had to be. For us.