The Person of Christ

What you'll learn

• State the doctrine of the person of Christ precisely: one person, the eternal Son, in two distinct natures, truly God and truly man, for ever
• Build the biblical case for Christ's eternal deity, true humanity, virgin birth, sinlessness and unity of person, and explain how Chalcedon (451) guards it
• Explain the threefold office of Christ and his two states of humiliation and exaltation, and show why each matters for the gospel

The doctrine in one sentence

Jesus Christ is the eternal Son of God who, without ceasing to be God, became truly man, so that he is now and for ever one person in two distinct natures, divine and human. That is the heart of what theologians call Christology, the doctrine of the person of Christ.

Every phrase in that sentence carries weight. "Eternal Son" means he did not begin at Bethlehem. "Without ceasing to be God" means the incarnation was an addition, not a subtraction. "Truly man" means a real body and a real human soul, not a costume. "One person" means there are not two Sons, a divine one and a human one, sharing a body. "Two distinct natures" means the divine and the human are not blended into a third thing. "For ever" means the incarnation is permanent: the Son did not lay aside his humanity at the ascension.

The Westminster Shorter Catechism puts it with great economy (Q21): the Redeemer is the Lord Jesus Christ, who, being the eternal Son of God, became man, and so was and continues to be God and man in two distinct natures and one person for ever. If you can explain each clause of that answer from Scripture, you understand the doctrine better than most church members. This lesson walks through it step by step. (The defensive case for Christ's deity against objectors is in Doctrines Under Fire, Lesson 2; here we go deeper into the doctrine itself.)

The eternal Son: true deity

The New Testament does not present Jesus as a man who became divine but as the divine Son who became man. John 1:1-3 is the starting point: "In the beginning was the Word, and the Word was with God, and the Word was God." Notice the three claims. The Word already was in the beginning (eternity). The Word was with God (personal distinction from the Father). The Word was God (full deity). Then verse 3 places him on the Creator side of the line: "All things were made through him." If all created things were made through him, he is not himself a created thing. Verse 14 then says that this Word "became flesh."

Paul reasons the same way. In Philippians 2:6-7 Christ was "in the form of God" and yet "emptied himself, by taking the form of a servant." The emptying is defined by the taking: he did not empty himself of deity but humbled himself by adding a servant's nature. Colossians 1:16-17 says all things were created through him and in him all things hold together, and Colossians 2:9 says "in him the whole fullness of deity dwells bodily." Hebrews 1:3 calls the Son "the radiance of the glory of God and the exact imprint of his nature," and Hebrews 1:8 applies Psalm 45 to him: "Your throne, O God, is forever."

The pattern is reinforced by how the apostles handle Old Testament texts about Yahweh. Isaiah 45:23 says every knee will bow to Yahweh; Philippians 2:10-11 says every knee will bow to Jesus. Joel 2:32 says whoever calls on the name of Yahweh will be saved; Romans 10:13 applies it to Jesus. The apostles were strict Jewish monotheists, and yet they placed Jesus inside the identity of the one God. Jesus himself claimed it: "before Abraham was, I am" (John 8:58), and Thomas confessed him as "My Lord and my God" (John 20:28) without rebuke.

This connects to the previous lesson. The Son is eternally begotten of the Father, "of one substance" (homoousios) with him, as Nicaea confessed. The person who became incarnate is the second person of the Trinity, not a lesser being.

The Son became man: incarnation, virgin birth and true humanity

Incarnation (Latin in carne, "in flesh") means the eternal Son took to himself a complete human nature. The Shorter Catechism (Q22) is precise: he took "a true body, and a reasonable soul." Both halves matter. In the fourth century Apollinarius taught that the divine Word replaced the human mind in Jesus. The church rejected this, reasoning as Gregory of Nazianzus famously put it, that what Christ did not assume he did not heal. If our minds are fallen, the Saviour needed a human mind to redeem them.

Scripture shows Jesus' humanity on every page. He was born and grew "in wisdom and in stature" (Luke 2:52). He was hungry (Matthew 4:2), tired (John 4:6), thirsty (John 19:28), he wept (John 11:35), was "troubled" in soul (John 12:27), and he died. He even says there is a day and hour that the Son does not know (Mark 13:32), which Reformed theologians explain as a limitation of his human knowledge, not of his divine nature. Hebrews 2:17 insists that "he had to be made like his brothers in every respect" so that he could be a merciful high priest.

The virgin birth, more precisely the virginal conception, is how the incarnation happened. Matthew 1:18-25 and Luke 1:26-38 both teach that Mary conceived by the power of the Holy Spirit without a human father, fulfilling Isaiah 7:14. It is not the reason Jesus is God (he was God before he was conceived), but it is the fitting sign that salvation comes from above, not from human initiative. It also shows that a new beginning entered the human race: the Son is truly descended from Adam through Mary, yet he is not simply one more child of Adam's line under Adam's headship.

Jesus was also sinless. He "knew no sin" (2 Corinthians 5:21), was "tempted as we are, yet without sin" (Hebrews 4:15), and was "a lamb without blemish or spot" (1 Peter 1:19). His temptations were real, because his human nature was real, but Reformed theology has usually added that he was not able to sin (Latin non posse peccare), since the person who was tempted is the eternal Son. Real temptation does not require the possibility of failure; it requires real pressure, and Christ felt it more than we do because he never gave in.

One person, two natures: how the church came to confess it

Once the church had confessed at Nicaea (325) that the Son is fully God, a second question followed: how do deity and humanity relate in Jesus? Two errors pulled in opposite directions. Nestorianism, associated with Nestorius of Constantinople, so stressed the distinction of the natures that it seemed to make two persons, a divine Son and a human Jesus joined in moral partnership. The Council of Ephesus (431) rejected this and approved calling Mary Theotokos, "God-bearer", not to exalt Mary but to insist that the one she bore is God the Son. Eutychianism, from the monk Eutyches, swung the other way and taught that after the union there was only one nature, the humanity being absorbed into the deity, as an old illustration put it, like a drop of honey in the sea.

The Council of Chalcedon (451), drawing on Pope Leo's Tome, set the boundaries. It confessed one and the same Christ, Son, Lord, Only-begotten, "to be acknowledged in two natures, inconfusedly, unchangeably, indivisibly, inseparably." These are the famous four "withouts": without confusion, without change, without division, without separation. The first two rule out Eutyches (the natures are not mixed, and neither is turned into the other). The last two rule out Nestorius (the person is not split, and the natures are never pulled apart).

The term for this union is the hypostatic union: the union of two natures in the one hypostasis (person) of the Son. A key clarification, worked out after Chalcedon, is that the human nature of Christ never existed as a separate person on its own; it was created and assumed in the very act of union and has its personal existence in the Son. So we do not say the Son joined himself to a man; we say he became man.

Later councils filled in details, such as Constantinople III (680-681) affirming two wills in Christ, a divine will and a human will, because will belongs to nature. Gethsemane shows the human will submitting: "not as I will, but as you will" (Matthew 26:39). The Reformers received Chalcedon gladly, and the Reformed confessions restate it (WCF 8.2; 1689 LBCF 8.2).

Key distinctions and common misunderstandings

Chalcedon is a fence, not a full explanation. It tells us where not to go rather than how the union works on the inside. That is fitting, because the incarnation is a mystery revealed, not a puzzle solved. Several distinctions keep us on the right path.

• Communicatio idiomatum (communication of properties): because the natures belong to one person, what is true of either nature can be said of the person. So Scripture can say "the Lord of glory" was crucified (1 Corinthians 2:8) and that God obtained the church "with his own blood" (Acts 20:28). The divine nature did not bleed, but the person who bled is God.
• The natures keep their properties. The divine nature does not become finite and the human nature does not become omnipresent. Reformed theology rejects the Lutheran idea that Christ's human body shares divine omnipresence, an in-house Protestant difference that shapes views of the Lord's Supper (see Lesson 8).
• The "extra Calvinisticum": Reformed theologians, following earlier fathers, taught that the eternal Son, while truly united to his flesh, was never confined to it; he continued upholding the universe (Hebrews 1:3) even while lying in the manger.
• Kenosis rightly understood: Philippians 2:7 does not teach that the Son gave up divine attributes. Modern "kenotic" theories that he laid aside omniscience or omnipotence would make him less than God during his earthly life.
• Not a hybrid. Jesus is not half God and half man, nor a God in a human suit. He is wholly God and wholly man.
• Not adoption. Jesus did not become the Son at his baptism; the voice from heaven declared who he already was.

The threefold office: prophet, priest and king

Who Christ is (his person) grounds what he does (his work). Reformed theology, especially since Calvin's Institutes (2.15), organises his work under three offices that in the Old Testament were filled by anointed men. "Christ" means "Anointed One", and he gathers all three anointings into himself.

As prophet he reveals God to us. Moses promised a prophet like himself (Deuteronomy 18:15; Acts 3:22), and Hebrews 1:1-2 says God has spoken finally "by his Son." He is not merely a messenger; he is the Word who makes the Father known (John 1:18). The Shorter Catechism (Q24) says he does this "by his Word and Spirit", which is why Scripture is the living voice of Christ to his church today.

As priest he offers a sacrifice and intercedes. Unlike Aaron's priests, he offered not animals but himself, once for all (Hebrews 9:12, 26), and he "always lives to make intercession" for his people (Hebrews 7:25). Lesson 6 develops his priestly work in the atonement.

As king he rules, protects and conquers. He is David's greater son (2 Samuel 7:12-16; Luke 1:32-33) who now has "all authority in heaven and on earth" (Matthew 28:18). He subdues his people to himself by grace, rules them by his Word, defends them, and will finally put all enemies under his feet (1 Corinthians 15:25). Only the God-man can hold all three offices: as man he can represent us, and as God his word, offering and reign have infinite worth.

The two states: humiliation and exaltation

Reformed theology also describes Christ's career in two "states". A state is a legal standing, not merely a condition. In his humiliation the Son placed himself under the law as our representative (Galatians 4:4). The Shorter Catechism (Q27) traces the downward path: born, and that in a low condition; made under the law; undergoing the miseries of this life, the wrath of God and the cursed death of the cross; buried; continuing under the power of death for a time.

In his exaltation the Father vindicated him (Philippians 2:9-11). Q28 traces the upward path: rising from the dead on the third day, ascending into heaven, sitting at the right hand of the Father, and coming to judge the world at the last day. It is still the God-man who is exalted. The divine nature cannot be raised higher, but the person of the Son, in his human nature and in his office as Mediator, receives the name above every name.

This framework helps you read the Gospels and Epistles. When Jesus is weary, ignorant of the day, or forsaken, you are seeing the state of humiliation. When he is raised "in power" (Romans 1:4) and enthroned, you are seeing the state of exaltation. It also helps the Christian life: the pattern of suffering first and glory after is the path he walked and the path he leads his people along (Romans 8:17; 1 Peter 5:10).

Why it matters, and where others depart

Everything in the gospel depends on the person of Christ. Only God can save, because salvation is a divine work and the debt of sin against an infinite God is infinite (Psalm 49:7-8; Jonah 2:9). Only a man can stand in for men, obey the law God gave to humans, and die (Hebrews 2:14-17). So the Mediator must be both. Anselm asked the question in Why God Became Man, and the Heidelberg Catechism (Q16-17) answers it the same way. Worship also depends on it: we may worship Jesus (John 5:23; Hebrews 1:6) only because he is God, and we may be comforted by him only because he is truly one of us (Hebrews 4:15-16).

Each group in this course departs from Chalcedon at a specific point. Jehovah's Witnesses teach that Jesus is Michael the archangel, the first creation of Jehovah, and they render John 1:1 as "a god" (Jehovah's Witnesses module). Latter-day Saints call Jesus divine but teach he is the spirit brother of all humans, a separate divine being from the Father, who (as LDS leaders have taught) attained godhood in the premortal life (Latter-day Saints module). Islam honours Jesus (Isa) as a sinless prophet born of a virgin, but denies he is the Son of God or God (Quran 5:72-75; 112) and that he was crucified (4:157) (Islam module). Judaism expects a human Messiah, not God incarnate (Judaism module). Some Hebrew Israelite camps teach a non-Trinitarian or adoptionist Christ (Hebrew Israelites module). Secular scholars often present a merely human Jesus later "divinised" by the church (Secular Society module). Roman Catholics confess Chalcedon with us; the differences lie elsewhere, in the application of Christ's work (Roman Catholicism module). Knowing exactly what Chalcedon says lets you locate each error quickly and lovingly.

Key texts

• John 1:1-3, 14: The Word is eternal, distinct from the Father, fully God and the Creator, and this same Word became flesh. The clearest one-passage summary of the incarnation.
• Philippians 2:5-11: The Son, in the form of God, humbled himself by taking the form of a servant, then was exalted. Shows the incarnation as addition, and the two states in one passage.
• Colossians 2:9: "In him the whole fullness of deity dwells bodily." Full deity and real body in one person, present tense.
• Hebrews 2:14-17: He shared in flesh and blood and was made like his brothers in every respect, so he could die for us and be a merciful high priest. The case for his true humanity.
• Hebrews 4:15: Tempted in every respect as we are, yet without sin. Grounds both his sympathy and his sinlessness.
• Luke 1:31-35: The virginal conception by the Holy Spirit, and the promise of David's throne. Links incarnation and kingship.
• Acts 20:28 and 1 Corinthians 2:8: God obtained the church with his own blood; the Lord of glory was crucified. Classic examples of the communication of properties.
• Hebrews 1:1-3: God has spoken by his Son, who made the world, upholds it, made purification for sins and sat down. Prophet, priest and king in three verses.

Objections and answers

Try answering each one yourself before you open the response.

Written task

In 300-400 words, explain in your own words to a new Christian in your church what it means that Jesus is "one person in two natures." Use Scripture to show that he is truly God, truly man and one person, explain one of Chalcedon's four "withouts" and the error it rules out, and finish with why this matters for their salvation or their prayers.

Hand this in to Mr Scott. He will look for:

• States the doctrine accurately in plain language (eternal Son, true deity, full humanity with body and soul, one person, for ever)
• Supports deity, humanity and unity of person each with at least one relevant text used correctly
• Explains at least one of Chalcedon's "withouts" and correctly names the error it answers (Nestorianism or Eutychianism)
• Shows why the Mediator must be both God and man, connecting the doctrine to the gospel or to prayer (Hebrews 4:15-16)
• Avoids common errors (kenotic loss of deity, half-and-half language, adoptionism) and uses a warm, teaching tone

Further reading

• The Person of Christ by Donald Macleod: A clear, reverent Reformed treatment of the incarnation, Chalcedon, kenosis and the sinlessness of Christ; the best next step after this lesson.
• God the Son Incarnate: The Doctrine of Christ by Stephen J. Wellum: A thorough modern evangelical Christology tracing the biblical storyline and the history from Nicaea to Chalcedon, with careful treatment of kenotic views.
• Reformed Dogmatics, Volume 3: Sin and Salvation in Christ by Herman Bavinck: The classic Reformed dogmatician on the person, offices and states of Christ; demanding but rich.