Understanding Christ’s Two Natures
For the past few weeks, my sermons have focused on Christ’s divinity; this Sunday, July 30, 2017, I’m preaching on the topic of Christ’s humanity. Since the 1st century AD, all Christians have held that Christ is 100% human and 100% God. Christ’s combination of human and divine natures is called the hypostatic union. The Church summarized this belief in the following quote from the Caledonian Definition of 451, which is well worth repeating at length:
“We teach with one voice that the Son [of God] and our Lord Jesus Christ is to be confessed as one and the same [Person], that he is perfect in Godhead and perfect in manhood, very God and very man, of a reasonable soul and [human] body consisting, consubstantial with the Father as touching his Godhead, and consubstantial with us as touching his manhood; made in all things like unto us, sin only excepted; begotten of his Father before the worlds according to his Godhead; but in these last days for us men and for our salvation born [into the world] of the Virgin Mary, the Mother of God according to his manhood. This one and the same Jesus Christ, the only-begotten Son [of God] must be confessed to be in two natures, unconfusedly, immutably, indivisibly, inseparably [united], and that without the distinction of natures being taken away by such union, but rather the peculiar property of each nature being preserved and being united in one Person and subsistence, not separated or divided into two persons, but one and the same Son and only-begotten, God the Word, our Lord Jesus Christ, as the Prophets of old time have spoken concerning him, and as the Lord Jesus Christ hath taught us, and as the Creed of the Fathers hath delivered to us.
That was a pretty deep with a lot of unusual vocabulary; the basic idea, however, is that Christ is completely God and completely human. So, when we talk about Christ, we have to say that He has a human nature and a divine nature which coexist in the one God-man whom we call Jesus. However, there are quite a few difficulties in this. For example, if Jesus is omniscient, then He can’t learn; however, Luke 2.52 says that Jesus learned things. Or, how could Jesus be omnipresent if He’s at a wedding in Cana of Galilee and not, say, in Jerusalem? One difficulty that I’ve found particularly interesting is how Christ could be God but still submit to God in a meaningful way.
Take, for example, Jesus’s famous prayer in the garden of Gethsemane immediately before His crucifixion. According to Matthew’s Gospel, Jesus prays: “Father, if it is possible, may this cup be taken from me. Yet not as I will, but as you will.” There are quite a few interesting things in this short prayer. For one, to avoid saying some pretty weird and heretical stuff, you need the doctrine of the Trinity. Without the Trinity, Christ is praying to Himself while acting like He’s praying to someone else, which is misleading and thus sinful. Another option would be to say that Christ is suffering from some delusion in which He thinks there is some being, “the Father,” to whom He can speak when He really can’t, which is rather odd. A strong doctrine of the Trinity alleviates the problem by saying that Christ is God the Son who is speaking to God the Father.
Second, and more to the point, if Christ is God and God wills that Christ go to the cross, then how can Christ pray this prayer? For, in this prayer, it sure does sound like Christ doesn’t want to be crucified—and that for good reason—yet is willing to go through it if it’s the Father will. But, if the Father is God and the Father wills it, then how can Christ be God and not will it?
The easiest way to answer this, in my opinion, is to follow Augustine of Hippo’s strategy and claim that Christ is speaking according to the human nature. That is, as a genuine human, Christ does not want to be crucified; nevertheless, He, as a human, chooses to be obedient to God.
This has some interesting applications to the other problems I mentioned above. Was Christ omnipresent when He was sitting at the wedding in Cana of Galilee? Well, in a sense, yes, He was; however, in another sense, no, He wasn’t. According to His divine nature, He is omnipresent; however, according to His humanity, He is not.
Here’s what’s driving all of this: When Jesus came to earth, He didn’t give up any divine attributes; rather, Christ took on those attributes which are essential to humanity. Therefore, when we talk about Jesus doing things that humans do, such as learning, being hungry, or growing, we are talking about things that Jesus did according to His human nature. These things reveal that His human nature was authentic. However, when we talk about Jesus doing things that only God could do, such as raising the dead, multiplying the equivalent of a Subway sandwich to feed thousands of hungry mouths, or turning water into wine, we are talking about things that Jesus did through His divine nature. These miracles reveal Christ’s divinity.
With this framework in mind, what does Jesus mean in Matthew 24.36 where He, speaking about when the end of the world will take place, says: “No one knows, not even the angels in heaven, nor the Son, but only the Father?”
Notes & Sources
 It’s interesting that they wanted to call Mary the Mother of God, yet were sure to say that Christ’s birth was for His human nature and not for His divine nature. That is, they want to call Mary the Mother of God without implying that God was born. I, like most Protestants, understand what the title “Mother of God” is meant to convey, but think that it’s unhelpful and misleading at very best.
 Matthew 26.39b, NIV.
 Matthew 24.36b, NIV.