It's nearly Christmas, and so the Incarnation is likely a topic you'll hear mentioned in sermons and Christmas carols. Songs about God being born as Jesus of Nazareth in Bethlehem are something that we hear all around us in the background as we're Christmas shopping or preparing dinners and attending parties.

But we often don't think deeply about why God had to become a human being.

Last year, I was a TA for a course on early church history. As part of this, I was able to give a lecture on Christological heresies—that is, basically "What Not to Say About Jesus".

As part of this lecture, I spent a little time on why it is theologically essential to say Jesus was fully divine while still being fully human.

The Biblical Evidence

Part of the early church's theological challenge was to figure out how to make sense of Jesus' claims about Himself, within the context of a religion that believes there is only one God.

For example, how do we make sense of Jesus' claims that:

• "Before Abraham was I am" (John 8:58-59).
• "I and the Father are one" (John 10:30-39).
• He has the authority to forgive sin (Matthew 9:2-6, Mark 2:5-10; Luke 7:47-48).
• His teaching is more authoritative than the Pharisees, the religious experts of that time (Matthew 12:8, 12:12, Mark 2:27-28, John 8:1-11).
• He would judge the world (Matthew 25:31-46, 28:18, John 5:22).
• He had the power to lay his life down and take it back up again (John 10:18).
• He had the authority and ability to give eternal life to His followers (John 10:28-29).

On top of this, we have Jesus' miracles and actions which confirmed these things. For example, his many miraculous healings, his authority over demons (Mark 1:27), his control over nature (Matthew 8:26-27), and his power to restore life (Mark 5:41, John 11:43-44) are all things only God can do.

Jesus also accepted worship of the disciples (Matthew 14:33, 28:17, John 9:38) and told them to pray to God in Jesus' own name (John 15:16, 16:23). This would have been blasphemy to the Jews, who were taught to only worship God, never angels or prophets.

All these claims were verified by Jesus' resurrection, by his ability to give the Holy Spirit to his followers (John 16:7, 20:22), and by his ascension to heaven (Luke 24:51; Acts 1:9, and Stephen’s vision in Acts 7:55-56).

So, it only makes sense, based on the Biblical evidence, to say Jesus is God. He's not just a prophet, or a good moral teacher, or a local unsuccessful revolutionary.

If we want to say that the disciples made all this up, it doesn't fit the facts.

Most of the disciples died in painful ways for their testimony that Jesus was indeed God and had been crucified, died, and came back to life. But people don't die for a lie they invented.

Plus, the Gospels contain many details and stories which make the disciples look foolish, and would not have been included if the disciples had decided to come up with this story to make themselves rich or famous (e.g. Matthew 16:23, 26:75) or even persuasive to others (e.g. having women be the first witnesses to Jesus' resurrection, and even the disciples didn't believe them at first (see Luke 24:10-11), for women were considered less reliable than men in that culture).

So saying that Jesus is fully God and fully human is really the only way to make sense of what Jesus said and did in the Gospels, and the spread of early Christianity, without saying that Jesus (and his disciples) were all liars or lunatics (as C.S. Lewis puts it).

But, theologically, there are several important reasons why we need to say Jesus is actually God Himself.

Reason 1: For Jesus To Be Our Perfect Sacrifice for Sin

First, Jesus had to be divine in order to be both sinless, and thus the perfect sacrifice for all humanity's sins while not needing to be redeemed Himself (Hebrews 7:26-27). No human besides Jesus has ever lived a perfect life (Isaiah 64:6, Romans 3:22-23).

He also had to be simultaneously fully human in order for that sacrifice to be applicable to humanity, for Christ to be our kinsman-redeemer, our high-priest (Hebrews 2:17), and for him to redeem all parts of our human nature (e.g. body/mind and soul/spirit).

Some reasons for how Jesus being fully human means our sins can be properly transferred to him has been touched on already in this post.

Reason 2: For Jesus To Perfectly Reveal God to Humanity

But, I think one of the most important reasons why we must say Jesus is God is so that we can know exactly what God is like.

Jesus said "Whoever has seen me has seen the Father" (John 14:9).

Not that Jesus is the Father (we're not Modalists) but that Jesus is a perfect representation of the Father's character to us, in a special and perfect way which involved God interacting with us in tangible ways that we could relate to (1 John 1:1).

T.F. Torrance, in his book The Mediation of Christ, has several excellent quotes that clearly show why we need to know that Jesus perfectly reveals God to humanity:

If there is no relation of mutual knowing and being and loving between the incarnate Son and the Father, then Jesus Christ does not... provide for us any guarantee in what he was or said or did as to what God is like in himself.1

Then,

Fearful anxiety arises in the human heart when people cannot connect Jesus up in their faith or understanding with the ultimate Being of God, for then the ultimate Being of God can be only a dark, inscrutable, arbitrary Deity whom they inevitably think of with terror ... it is quite different when the face of Jesus is identical with the face of God, when his forgiveness of sin is forgiveness indeed for its promise is made good through the atoning sacrifice of God in Jesus Christ, and when the perfect love of God embodied in him casts out all fear. But all that depends upon the identity between Christ’s mediation of divine revelation and reconciliation and his own Personal Being as Mediator.2

So basically, if Jesus is God, then we can have confidence about God's character, God's love for us, and God's forgiveness of our sins, because Jesus has demonstrated all of these to us in His earthly life, death, and resurrection.

We don't have to be afraid that while Jesus is kind, loving, and forgiving, God the Father might actually be strict, angry, wrathful, and unforgiving.

Unfortunately, this is the impression of God that we often get, both from bad theology, and also popular depictions of God in our culture.

For example, I remember a song by the Christian artist Carman, titled "The Courtroom", where he depicts the final judgment as a trial where God the Father is the judge, Jesus is our defense attorney, and Satan is the prosecutor.3 It's up to Jesus to prove your case before God, who may (or possibly may not) forgive your sins. It subtly implies that there is some difference between Jesus and God, that Jesus loves you and forgives you, but God the Father is not quite so sure unless Jesus can present a good case on your behalf.

Somehow, whether it was from this song or elsewhere, I grew up with the impression that maybe, even if Jesus loves me, God the Father might not; God the Father might still be angry at me. Jesus might lose his court case, or maybe, if the Calvinists are right, God actually has predestined me to hell after all, and Jesus' death doesn't apply to me.

It has taken a long time and lots of study to correct my thoughts about God the Father to get over this impression, and like Torrance says above, to realize Jesus does perfectly represent the Father.

There is no chance that Jesus wants to forgive me but God the Father wants to send me to hell instead. Both the Father and the Son (Jesus) are perfect Love (1 John 4:8, 4:16), and perfect light and holiness with no darkness or evil in them at all (1 John 1:5).

Unfortunately, I still have difficulty praying to God as "Father", because the term "God the Father" still brings up ideas of the vindictive, arbitrary, and wrathful God who wants to send me to hell, and so it's easier for me to pray to Jesus instead.

So this is one reason why we need to be really careful in what we say about God the Father and his relationship to Jesus; if there's even a hint that they are not part of the same Triune Deity and have the exact same character, then there's no guarantee that what Jesus says reflects God the Father accurately.

As I've experienced, this can really mess up a person's view of God, which, in my case, even years of theological training has a hard time fully undoing.

Excursus: Was Jesus Fully Incarnate?

One interesting and related debate between Calvinists and Lutherans is whether the Son of God was fully incarnate in the person of Jesus.

Calvin argued that the infinite divine nature of the Son could not possibly become fully incarnate in the finite human Jesus. Instead, he said,

The Son of God descended from heaven in such a way that, without leaving heaven, he willed to be borne in the virgin’s womb, to go about the earth, and to hang upon the cross; yet he continuously filled the world even as he had done from the beginning.4

Basically, to Calvin, trying to fit the infinite divine Son into the finite human Jesus is kind of like when we try to squeeze into a pair of jeans that is just too small—there is some part of us that overflows the jeans and can't be contained in them, no matter how hard we try.

So Calvin says the Son was only partly incarnate in the person Jesus, but not entirely.

But, the problem is, if this was true, then the finite portion of the divine Son which could "fit" into the human Jesus would be infinitely small in comparison to the portion of the Son which was not incarnate. Instead of mostly fitting into those tight human jeans (or genes), He can barely fit even a toenail!

So, I prefer the Lutheran claim, that somehow, the finite can contain the infinite, so that the Son, the Second Person of the Trinity, was somehow fully incarnate in the finite human person of Jesus.

This is the only way we can be sure that Jesus truly and fully represented God.

Otherwise, who knows if there might not be some part of the Son who is actually not kind, not forgiving, and not loving, and maybe even downright evil?

(Although, Calvin's representation of God would actually fit with that, since he says God predestines most people to infinite torture in hell and these people never had any real opportunity to believe in Christ and be saved. In comparison, this sort of god would make Hitler, Stalin, Mao, Genghis Khan, and others seem like pretty decent people!)

In conclusion, if Jesus was not the full and complete incarnation of the Son, then he could not be the perfect representation of God the Father to us either.

Reason 3: To Avoid Misconstruing the Atonement

Theologically, the penal substitution theory of the atonement often claims that God the Father is angry at our sin and must punish us because of it, but Jesus, who loves us, says to God:

Hey, wait a minute—I love all those people, and I don't want them to all be destroyed. So how about you send me down there and you punish me instead? That way, you get to vent your wrath at sin and the punishment that is due for sin is paid by me, so that then you can forgive them!

This is often characterized by atheists as "cosmic child abuse", because it depicts God as punishing his Son, who became incarnate as Jesus Christ, for our sins instead of God punishing us.5

Of course, penal substitution is a powerful way of understanding the atonement and does have Biblical support (e.g. 2 Corinthians 5:21, Isaiah 53:4-6, Galatians 3:13, 1 Peter 2:24, 3:18). Penal substitution is also illustrated historically in how Jesus was tortured and killed while the terrorist Barabbas was set free (Matthew 27:26).

But, we need to remember that the Son is fully God and is equal in every way with the Father! So God is not punishing some innocent third-party on the cross—God is actually absorbing His own wrath at sin, through the Son who is incarnate as Jesus. Now there is nothing left for us except love and forgiveness if we believe in Christ.6

Timothy Keller has a very helpful explanation of why God had to either inflict His wrath at sin on us or absorb it into Himself. In his book The Reason For God, Keller says that if someone hurts us, for example, by damaging our property which must then be fixed, there are only two options: either the perpetrator pays the cost, or the one whose property is damaged pays the cost. In relationships when one party is hurt by another, either we vent our anger on the person who has hurt us, or we absorb our own anger so that we can forgive them.7

He writes:

To refrain from lashing out at someone when you want to do so with all your being is agony. It is a form of suffering. You not only suffer the original loss of happiness, reputation, and opportunity, but now you forgo the consolation of inflicting the same on them. You are absorbing the debt, taking the cost of it completely on yourself instead of taking it out of the other person. It hurts terribly. Many people would say it feels like a kind of death.8

The cross is therefore God's ultimate demonstration of God's love and righteous justice, simultaneously. God's holiness means He can't ignore our sin, but must deal with it as it deserves, and yet He does this at great cost to Himself because He loves us.9

We can see what this cost Him in the time between when Jesus cried out "My God, my God, why have you forsaken me?" (Matthew 27:46, a reference to the Old Testament foreshadowing of the cross in Psalm 22), and when He finally died and said, "It is finished" (John 19:30).

Somehow, the eternal intra-Trinitarian perfect love and intimacy between the Father and Son was interrupted temporarily, when God the Son was experiencing and absorbing the spiritual suffering and abandonment by God the Father which all humans deserve for our sins.10

I think the physical torment of the cross would have been miniscule in comparison to this spiritual suffering. Perhaps God chose crucifixion as a physical illustration of the sort of terrible suffering the Son of God was experiencing behind the scenes in the spiritual dimension of reality, so that we could get a small picture of what he was going through?

But, if Jesus was not God in human flesh, then none of his sufferings, whether physical or spiritual, could do anything to reconcile us to God. A finite creature could never fully bear God's infinite holy punishment at sin. But because Jesus was God, his temporary sufferings, experienced in his infinite divine nature, can pay for every sin that every human could possibly commit.

Conclusion

The Incarnation is really a mystery. No one but Jesus knows what it is like to be fully human and fully divine simultaneously, or what he experienced on the cross.

Yet the Incarnation is also a really critical piece of Christian theology, for we must say that Jesus was the full and perfect representation of God, and the only one who could properly atone for our sins and reconcile us to God, for He truly was and is "God With Us" (Emmanuel).

Footnotes:

• 1. T. F. Torrance, The Mediation of Christ, New Edition (Colorado Springs, CO: Helmers & Howard, 1992), 59.
• 2. T. F. Torrance, The Mediation of Christ, New Edition (Colorado Springs, CO: Helmers & Howard, 1992) 59-60.
• 3. Carman Licciardello "The Courtroom | Music Videos | Carman", YouTube.com, April 26, 2016.
• 4. John Calvin, Institutes of the Christian Religion Book 2, ed. John T. McNeill, trans. Ford Lewis Battles (Louisville, KY: Westminster John Knox Press, 2011), 2.13.4.
• 5. Donald Macleod, Christ Crucified: Understanding the Atonement (Downers Grove, IL: IVP Academic, 2014), 63-64.
• 6. Timothy Keller, The Reason for God (New York, NY: Riverhead Books, 2008), 200. See also Donald Macleod, Christ Crucified: Understanding the Atonement (Downers Grove, IL: IVP Academic, 2014), 64.
• 7. Timothy Keller, The Reason for God (New York, NY: Riverhead Books, 2008), 194-195.
• 8. Timothy Keller, The Reason for God (New York, NY: Riverhead Books, 2008), 196.
• 9. Donald Macleod, Christ Crucified: Understanding the Atonement (Downers Grove, IL: IVP Academic, 2014), 115.
• 10. Donald Macleod, Christ Crucified: Understanding the Atonement (Downers Grove, IL: IVP Academic, 2014), 48.