Doctrine: Genuine Humanity of Christ

What would you say if your friend insisted that Christ could sin, but just decided not to?

Or if a neighbor told you that He was actually half God and half man? Perhaps your co-worker argued that Christ had a human body, but not a spirit or will. How would you respond?

The humanity of Christ is essential for all of us to understand, and perhaps no one has expressed this better than C. H. Mackintosh: The truth respecting Christ’s humanity must be received with scriptural accuracy, held with spiritual energy, guarded with holy jealousy, and confessed with heavenly power. If we are wrong as to this, we cannot be right as to anything.”

It is true that most of the recent assaults against the person of Christ have been leveled against His deity. Yet while the fact of His manhood is rarely questioned today, the nature of His humanity is frequently misunderstood.

In fact, many of the heresies that faced the early Christian church dealt with this subject. Did Christ only appear to have a human body, as the Docetics claimed? Or, as Apollinaris taught, did He have a real body, but not a human mind? Was Nestorius right in believing that Christ was actually two separate people? Or were His two natures merged into one – a third nature, neither truly human nor truly divine – like Eutychius thought?

Thankfully, early believers examined and refuted each of these teachings. They insisted that Jesus Christ was not only fully God, but also fully man – genuine in every way, apart from sin.

But let us consider these issues ourselves. Was Christ actually a real man, or did He just appear to be? Was humanity necessary for our salvation? And if so, does this mean that He was susceptible to sin as we are?

Of the various issues surrounding the humanity of Christ, we’ll begin with the easiest to establish. The Scripture is clear: Jesus Christ was a real man, a descendant of David (Rom 1:3). His humanity was prophesied from the very beginning (Gen 3:15), typified in the Old Testament experiences of Israel (e.g., Exo 16, John 6:33), and verified by the prophets (e.g., Isa 9:6).

But a day came when all the types and prophecies were realized. An ordinary woman (a virgin!) gave birth to a real baby boy, who “increased in wisdom and in stature, and in favor with God and man” (Luke 2:52, ESV). He was not simply God wearing a human skin, but was a genuine man, in full possession of body (Heb 10:5), soul (Matt 26:38), spirit (Luke 23:46), and will (Luke 22:42). He ate and he drank; He was tempted, and He wept. God could not be troubled, but Christ was. God could not grow weary, but Christ did. God could not suffer and die, but Christ died.

Perhaps the deepest glimpse into this reality is seen in His suffering. He was a “man of sorrows” (Isa 53:3), and said that “reproach has broken my heart” (Psa 69:20, KJV). Either He was a real man, experiencing pain, deprivation, sorrow and rejection, or the cross was just a cruel illusion.

We should be left with no doubt – Jesus Christ was a real man, with all the limitations and sorrows of humanity. But, He was absolutely unique, “for in Him all the fullness of deity dwells in bodily form” (Col 2:9, NASB).

But if the reality of His humanity is clear, perhaps the reason for it is less so. Couldn’t Christ have done everything without the incarnation? Was humanity really necessary? As we’ll see, if Christ was going to redeem, restore, and intercede for men, He had to come into the world as a man Himself.

In fact, the message of the Bible is consistent from the beginning: “Without shedding of blood there is no forgiveness of sins” (Heb 9:22, ESV). Sinful humanity required a sacrifice – one of infinite value, and one that would be sufficient once and for all. Who other than God could provide such a sacrifice? So Christ became a man (for God cannot die) to “taste death for every man” (Heb 2:9). If He was anything less than truly God, and anything other than truly man, He never could have provided salvation.

But Christ was not just any man. He was the “last Adam,” the one who will restore everything lost by the first man. God always intended for a man to have dominion and authority over the world (Gen 1:26). Of course, the first Adam fell, introducing sin and death, losing the position that God had given him. But Christ, a real Man, has fulfilled everything that God ever intended (1Cor 15:45-49; Rom 5:18; Heb 2:14). He is the Son of Man, perfectly exhibiting the image of God. God’s original purpose will be accomplished: a real Man will one day rule over all things (1Cor 15:25; Heb 2:5-9).

Before moving on, we need to point out a key distinction: Christ was not a fallen man. Unlike us, Adam was not his legal representative; He did not inherit Adam’s sinful nature. In other words, Christ did not possess original sin. We’ll return to the issue of His sinlessness later (Rom 5:19, 8:3; 1Cor 15:22).

Even though the work of redemption is finished, Christ is still a man today – our Great High Priest, interceding for us (Heb 2:17-18). As we’ve seen, we needed someone great enough to reach the throne of God, yet also able to sympathize with our weakness (Heb 4:15). Thank God for a real Man in heaven today!

But how could Christ be both God and man? As we’ve mentioned, this was one of the primary struggles of the early church. Here we must tread carefully, always cautious to defend both the reality of His deity and of His full humanity.

Enigmatically, the New Testament teaches that Christ was both God and man. The gospel writers record Him sleeping, but then He stills the waves. He is about to die, yet claims authority over angelic legions. There are clearly not two people acting; there is only one Christ. So how can a single person be demonstrating both deity and humanity, while not compromising either?

As early Christians worked to clearly express this tension, the term “hypostatic union” emerged. Simply put, the doctrine of the hypostatic union teaches that Christ possessed two natures: one human and one divine. These natures were united – inseparably, indivisibly, and without confusion – in the single person of Jesus Christ.

But as we’ve mentioned, these natures were not confused, nor mixed together. God is immutable; He cannot change. If Christ’s divine nature were mixed with the human nature, He would possess a third, separate nature: something not quite God and not quite man. Something that is half God and half man is a demigod. Think of a mythical centaur! In contrast, Christ was 100 percent God and 100 percent man. These natures are distinct from one another: we must be careful to distinguish them from each other, while guarding against separating them.

You see, not only are these two natures distinct, they are indivisible. While we observe the single person of Christ doing things that only God can do, and also doing things that only man can do, we must remember that a nature is not an agent. In other words, natures cannot do things – only a person can. Therefore, we shouldn’t say that “Christ did this as God,” or “He did this as man.” This implies the existence of two persons, which is historical Nestorianism.

In summary, the eternal Son of God came into the world and added to the divine nature a human nature – something that He did not possess before (Phil 2:7; John 1:14). The human nature was not absorbed into the divine, nor did the divine nature morph into something new. In the words of Gregory of Nazianzus: “What He was not He became, who He was He remained.”

As we’ll see, the fact of the hypostatic union has enormous consequences for the sinlessness of Christ.

There is really no question that the Savior did not sin. The Scripture is clear: He did no sin; He knew no sin; in Him is no sin. Yet as we approach the problem of impeccability, we are really moving to a far greater question. He did not sin, true. But could He have sinned, perhaps in a moment of extreme temptation? And if not, why not?

First, let’s consider the fact that he did not sin. We must ask ourselves how Christ could live a holy life. Many times the answer to that question simply invokes His deity: “He was God!” and of course, that is true. But the reality is that Christ did not simply assert His deity any time He was faced with temptation. How, then, did He overcome?

The answer is found clearly and wonderfully in the gospel narratives. He was the ideal man, anointed, driven and controlled by the Spirit of God. In the wilderness, He overcame Satan with the Word of God. In the course of His life, even to the very end, He was found in prayer. In other words, the perfectly obedient man led a holy life through the same means that we have: the Spirit of God, the Word of God, and prayer.

But this does not answer the question as to whether He could have sinned. And here we must remember two things we addressed earlier. First, Christ did not possess a fallen human nature. And second, that human nature was inseparably joined to the divine. Of course, God cannot sin; God is holy. Sin would violate this holiness, and (ultimately) would be rebellion against Himself – an absolute contradiction.

Let us bring these two great claims together. Christ is fully God, and fully unfallen, obedient, ideal man. Not only did He live a perfect, obedient life, but He must have been, in the harmony of His two natures, absolutely impeccable – that is, incapable of sinning.

But this leads us to another question. If Christ could not sin, were His temptations real? After all, if we could not fall, wouldn’t overcoming sin be no struggle at all?

Here we must distinguish between external temptation, and our internal response. There is nothing sinful about being tempted; it is only sinful to yield. Christ was certainly tempted, in the sense that solicitations to sin and to deviate from His purpose were hurled against Him. He was not only tested and proven to be the Son of God, but was actively tempted by Satan. Yet He was never “drawn away of his own lust and enticed”’ (James 1:14, KJV). Sin found no foothold in Him.

Indeed, the temptation that Christ experienced was of a magnitude far greater than our own. He “suffered being tempted” (Heb 2:18, KJV), and to His holy soul temptation must have been intensely painful. Think of it: a whole life lived with no margin of error. So, while Christ did not succumb – nor could have succumbed – to temptation, He, in every sense, experienced its suffering. “Christ, because He was the only man who never yielded to temptation, is also the only man Who knows to the full what temptation means” (C.S. Lewis).

As we’ve seen, you and I have a Savior that is both fully God and fully man. Everything depends on His complete, genuine humanity. Not only has He died for us, but He lives – our great high priest, who experienced the sufferings and temptations of life in this world. As we live for Him, let us always defend the singularity of His person, the distinction of His natures, and His absolute impeccability. May we all grow in devotion to “the man Christ Jesus, Who gave Himself a ransom for all” (1Tim 2:5, KJV).