Jesus slept in a boat because He was weary. Then He arose and commanded the wind and the sea, and they obeyed Him.
He grew in wisdom, yet He knew what was in man. He was tempted, yet without sin. He said that He did not know the hour of His return, yet His disciples confessed that He knew all things. He suffered, bled and died, although God is immortal.
Christians rightly believe all these things because Scripture plainly teaches them. The difficulty begins when we try to explain how they can all be true of the same Christ.
It is common to hear that Jesus did one thing “as God” and another “as man.” There is truth behind that language, but it can easily become misleading. We may begin to imagine a divine Jesus and a human Jesus taking turns: the man sleeps, but God performs the miracle; the man does not know, but God knows; the man suffers, while the Son of God remains at a distance.
That is not the Jesus of Scripture. The one who slept is the one who stilled the sea. The one who grew in wisdom is the one through whom all things were made. The one who died upon the cross is the Lord of glory.
To speak faithfully, we need to distinguish Christ’s two natures without dividing Christ Himself.
Who He Is and What He Is
The basic distinction is not as difficult as its theological vocabulary may suggest:
Person tells us who Jesus is. Nature tells us what He is.
Who is He? He is the eternal Son of God, the Word who was with God and was God.
What is He? He is truly God and truly man.
Jesus Christ is one Person possessing two complete natures: a divine nature and a human nature. He did not cease to be God when He became man, nor did His deity replace any part of a real human life. “The Word was made flesh, and dwelt among us” (John 1:14). The eternal Son did not unite Himself to a separate human person. He Himself took our nature and became man.
This is why the child born at Bethlehem could be called “The mighty God” (Isaiah 9:6), and why Thomas could look upon the risen Jesus and confess, “My Lord and my God” (John 20:28). The baby, the boy, the teacher, the crucified one and the risen Lord are one and the same Person.
At the same time, His humanity was no appearance or disguise. He “was made of the seed of David according to the flesh” (Romans 1:3). He possessed a real human body and a rational human soul. He experienced hunger, thirst, weariness, sorrow and pain. He learned, obeyed, prayed and was tempted. “In all things it behoved him to be made like unto his brethren” (Hebrews 2:17), yet always “without sin” (Hebrews 4:15).
His deity remained complete: “In him dwelleth all the fulness of the Godhead bodily” (Colossians 2:9). His humanity was also complete. He is not half God and half man, nor a third kind of being produced by blending the two. He is fully God and fully man.
Natures Do Not Speak—Persons Do
Here lies one of the most important safeguards in the doctrine.
A nature is not an independent actor. Christ’s human nature does not speak, obey or suffer by itself. His divine nature does not step forward to preach, forgive sins or work a miracle. The Person acts through and according to His natures.
We may therefore distinguish what Christ does according to His deity from what He does according to His humanity. But we must not turn those distinctions into two acting subjects.
It is better to say:
The Son was weary according to His human nature.
than:
The human Jesus was weary.
The first statement distinguishes His natures while preserving the one Person. The second can suggest that there is a human person alongside the divine Son.
The same care is needed when people speak of Christ’s “divine side” and “human side.” Jesus is not divided into two sides or halves. Everything He does is done by the one Lord Jesus Christ, although not everything He does belongs to both natures in the same way.
This gives us a useful rule:
We may distinguish what Christ experienced or did according to either nature, but we must not divide the one Christ who experienced or did it.
The Lord Who Slept and Stilled the Sea
Mark tells us that Jesus was “in the hinder part of the ship, asleep on a pillow” while a storm filled the boat with water (Mark 4:38). His sleep was real. The eternal Son had entered fully into human weakness and weariness.
When His disciples woke Him, He rebuked the wind and said to the sea, “Peace, be still.” The wind ceased, and there was a great calm. The disciples responded, “What manner of man is this, that even the wind and the sea obey him?” (Mark 4:39–41).
We should not describe the scene as though the man were sleeping until God awoke to perform the miracle. The same Person did both. The Son slept according to the limitations of His humanity and exercised divine authority over creation. The Gospel does not alternate between two Christs. It reveals the one Christ in the truth of both His natures.
How Could Jesus Grow in Wisdom?
Luke writes that “Jesus increased in wisdom and stature, and in favour with God and man” (Luke 2:52). If Jesus is God, and God knows all things, how could He increase in wisdom?
The answer is not that the divine nature became wiser. God does not develop from ignorance into knowledge. Neither was there a merely human person growing alongside the eternal Son.
The Son of God had assumed a complete human nature and therefore lived a genuinely human life. As man, He passed through infancy and childhood. He learned to speak, read and work. His human mind developed in the proper manner of a sinless human life.
The one who grew was the divine Person, but He grew according to His humanity. There is no contradiction in saying that the Son possessed divine omniscience according to His divine nature while genuinely increasing in human knowledge according to His human nature. The statements concern the same Person, but not the same nature.
If we deny that growth, His humanity becomes unreal. If we make His divine nature grow in knowledge, His deity becomes changeable. The distinction protects both truths.
Did the Son Know the Hour?
The same distinction helps us approach one of Christ’s most difficult sayings:
“But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father.”
Mark 13:32
We must resist the temptation to answer by creating two speakers. It was not a separate human Jesus who lacked knowledge while a divine Jesus silently knew everything. There is only one Son.
The Son truly participated in the limitations proper to human knowledge. He could therefore say that He did not know the hour according to His human nature, while remaining omniscient according to His divine nature.
This is mysterious, but it is not a contradiction. A contradiction would require us to say that Christ both knew and did not know the hour in precisely the same respect. The distinction of natures explains why that is not what Christians confess.
Scripture itself compels us to hold the truths together. The same Gospel that records Christ’s growth in wisdom also shows Him knowing what was in man (John 2:24–25). His disciples could say to Him, “Now are we sure that thou knowest all things” (John 16:30), and after the resurrection Peter appealed to that knowledge: “Lord, thou knowest all things” (John 21:17).
We should not remove one set of passages to make the other easier. Faithfulness requires us to confess everything Scripture says.
Could Jesus Truly Be Tempted?
James tells us that “God cannot be tempted with evil” (James 1:13), while Hebrews says that Christ “was in all points tempted like as we are, yet without sin” (Hebrews 4:15).
Christ’s temptations were not theatrical. Hunger, suffering, rejection and the prospect of the cross were genuinely experienced in His humanity. Yet temptation never encountered sinful desire within Him. The prince of this world came and had nothing in Him (John 14:30).
The Person tempted was the Son of God; the temptations reached Him through the human life He had truly assumed. His divine nature did not become corruptible or capable of evil. His sinlessness did not make the trial unreal. It made His obedience perfect.
Once again, the distinction prevents two opposite mistakes. We must not attribute moral weakness to His deity, and we must not protect His deity by making His human experience an illusion.
Did God Suffer and Die?
The cross makes careful language unavoidable.
God, in His divine nature, is immortal. Deity cannot cease to exist, bleed or be separated into soul and body. Yet the New Testament does not permit us to say that an independent human person died while the Son of God remained untouched.
Paul says that the rulers of this world “crucified the Lord of glory” (1 Corinthians 2:8). Acts speaks of “the church of God, which he hath purchased with his own blood” (Acts 20:28). The one who shed His blood is identified by who He is: the Lord of glory, the Son of God.
We may therefore say that God the Son suffered and died, provided we understand that He suffered and died according to His human nature. We should not say that the divine nature suffered or died. The suffering belongs personally to the Son because the humanity in which He suffered was truly His.
This is sometimes called the communication of properties. The expression does not mean that the properties of humanity are transferred into deity, as though the divine nature became mortal. It means that what belongs to either nature may be truly spoken of the one Person whose nature it is.
The baby lying in the manger is the Creator, although creation does not belong to His infancy. The man who thirsted beside the well is the giver of living water. The one whose hands were nailed to the cross is the Lord of glory. The statements are astonishing because of the identity of the Person, not because deity has been changed into humanity.
At death, Christ’s human soul was separated from His human body. Yet neither was separated from the Person of the Son. The body placed in the tomb was His body; the spirit committed into the Father’s hands was His human spirit. The Son did not cease to exist, nor did the union established in the incarnation collapse.
The death was therefore genuinely human and personally divine: the Son of God died for us according to the humanity He had made His own.
Why the Early Church Struggled for Words
Christians did not begin with philosophical definitions and then impose them upon Jesus. They began with the apostolic testimony. The need for precise language arose because people offered explanations that preserved some biblical statements by sacrificing others.
Some denied that Christ possessed a complete human mind or soul. Others treated His body and suffering as appearances. Some blended deity and humanity until His humanity was no longer like ours. Others distinguished them so sharply that Christ seemed to become two acting persons joined together.
These were not arguments over empty words. If Christ did not assume a complete human nature, then He did not become like His brethren in all things. If His humanity was swallowed up by His deity, He cannot truly represent us. If He is divided into two persons, it becomes difficult to say that the Son of God Himself loved us and gave Himself for us.
The controversy associated with Nestorius arose in this setting. Nestorius feared that certain language about Mary confused Christ’s humanity and deity. There was a legitimate concern behind that fear: Mary did not originate His divine nature and cannot be described as mother of the Father or of the Holy Ghost.
His opponents, especially Cyril of Alexandria, feared that Nestorius’s manner of speaking divided Christ into two personal subjects. Their use of the Greek word Theotokos, literally God-bearer, was intended to protect the identity of the one Mary bore. The child conceived and born of her was not a separate human person later joined to God. He was the eternal Son incarnate.
Understood in that historical sense, Theotokos makes a correct statement about the Person of Christ. It does not mean that Mary was the source of His deity or existed before God. Nevertheless, “Mother of God” now carries other devotional and theological connotations, and the word “God” used without qualification does not distinguish the Persons of the Trinity. Mother of Christ or Mother of the Son of God therefore expresses the truth more clearly, while God-bearer remains useful when explaining the historical controversy.
Nestorius’s language required examination and correction, but that does not require us to approve of everything done to him. The Council of Ephesus in AD 431 was marked by rivalry, political pressure and disputed proceedings. Nestorius refused to appear before an assembly presided over by Cyril, his principal opponent, and wanted the council to wait for the bishops from Antioch. He was condemned and deposed in his absence, and after continuing to defend himself he was eventually subjected to a harsh exile.
We can therefore reject any division of Christ without turning Nestorius into a caricature or treating his suffering as deserved. Historical fairness does not weaken doctrinal conviction.
Four Guardrails Around the Mystery
At the Council of Chalcedon in AD 451, the Church described Christ as one and the same Son, complete in deity and complete in humanity, existing in two natures:
- Without confusion: His deity and humanity are not blended into a mixture.
- Without change: the divine nature did not turn into humanity, nor did humanity become deity.
- Without division: Christ is not divided into two persons.
- Without separation: His two natures are not detachable parts or independent centres of personal life.
These words do not explain how the incarnation was accomplished. They are guardrails telling us what Scripture will not allow us to say.
Chalcedon did not make Jesus become one Person in two natures in AD 451. Nor does accepting its teaching require us to treat a council as infallible. Its definition is valuable insofar as it faithfully brings together truths already revealed in Scripture.
The doctrine must always be tested from the Bible. When tested in that way, the four guardrails are profoundly useful: do not confuse the natures, change either nature, divide the Person or separate what God united in the incarnation.
Why Ordinary Christians Need This Distinction
It is possible to repeat an orthodox confession without knowing why it matters. But the distinction between Person and nature becomes practical as soon as we begin reading the Gospels carefully.
Without it, we will tend to fall into one of two errors.
The first is confusing the natures. We may speak as though the divine nature became ignorant, developed, suffered or died. In trying to honour the unity of Christ, we make deity changeable and mortal.
The second is dividing the Person. We may assign some sayings to “the human Jesus” and others to “the divine Jesus,” as though two persons occupied the same life. In trying to protect the distinction of natures, we lose the one Christ.
The biblical confession avoids both:
What belongs properly to either nature may be attributed to the one Person whose nature it is, but it must not therefore be transferred to the other nature.
Thus we may say that the Son of God was born, hungered, suffered and died, because the Person who experienced those things is the Son of God. We do not say that the divine nature was born, became hungry or died, because He experienced those things according to His humanity.
Similarly, we may say that the man Christ Jesus forgave sins, received worship and will judge the world, because the man is not a separate human person. He is the eternal Son living and acting in the humanity He assumed.
This is not theological fussiness. It is learning to speak truthfully about the Lord we worship.
Why It Matters for Salvation
Our salvation depends upon Christ being precisely who Scripture says He is.
He must be truly man to stand in our place. “For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous” (Romans 5:19). He obeyed where Adam disobeyed. He possessed the blood He would shed, the body He would offer and the human life in which He would endure temptation without sin.
He must be truly God to reveal the Father perfectly and save completely. No mere creature could bear the identity, authority and glory Scripture gives to Him. The salvation accomplished at Calvary possesses immeasurable worth because the Person who offered Himself is the eternal Son.
And He must be one Person. The cross is not the story of a righteous man suffering while the Son of God watches or works through him from a distance. Paul writes of “the Son of God, who loved me, and gave himself for me” (Galatians 2:20). The Person who loved us is the Person who gave Himself.
The incarnation also continues to matter after the resurrection. Christ did not discard His humanity when He left the tomb. The risen Lord could say, “Handle me, and see; for a spirit hath not flesh and bones, as ye see me have” (Luke 24:39). He ascended bodily and remains “the man Christ Jesus” who mediates between God and men (1 Timothy 2:5).
Because He is truly man, He is our brother, representative and merciful High Priest. Because He is truly God, He is able to save to the uttermost. Because He is one Person, these are not the works of two cooperating saviours. They are the work of the one Lord Jesus Christ.
The One Christ We Worship
We do not worship Christ’s deity while merely acknowledging His humanity. Nor do we worship a human Jesus alongside the eternal Son. We worship one Person: Jesus Christ, the Word made flesh.
The one in the manger is the one who made the worlds. The one who learned obedience is the one whom angels worship. The one who wept at Lazarus’s grave is the resurrection and the life. The one who cried, “I thirst,” is the fountain of living waters. The one who was crucified in weakness is the Lord of glory. The one who rose bodily from the grave is coming again in power.
We cannot explain the incarnation by reducing it to something ordinary. It remains “the mystery of godliness: God was manifest in the flesh” (1 Timothy 3:16). But mystery does not release us from speaking carefully. Scripture has told us enough to keep us from confusing His natures or dividing His Person.
Jesus Christ is one and the same Son: truly God, truly man, crucified, risen and coming again.
And because the one who gave Himself for us is both God and man, He is the perfect and sufficient Saviour.