Devotional 45: The Two Natures of Christ: Truly God and Truly Man

The Confession Read

The Son of God, the second person in the Trinity, being very and eternal God, of one substance and equal with the Father, did, when the fulness of time was come, take upon him man's nature, with all the essential properties and common infirmities thereof, yet without sin; being conceived by the power of the Holy Ghost in the womb of the Virgin Mary, of her substance. So that two whole, perfect, and distinct natures, the Godhead and the manhood, were inseparably joined together in one person, without conversion, composition, or confusion. Which person is very God and very man, yet one Christ, the only Mediator between God and man.

— Westminster Confession of Faith, Chapter 8, Section 2

Introduction

Somewhere in the dusty hill country of Judea, in a village whose name the prophets had never once spoken, a girl of perhaps fourteen years felt a stirring in her womb that was not from Joseph. The angel had come and gone, his words still burning in her memory like embers after a fire: "The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee." And in that moment of divine overshadowing, by an act more intimate than any natural conception and more creative than the word that called the stars into being, the eternal Son of God, who had never ceased to be what He was, began to be what He was not. The second person of the Trinity, by whom all things were made, became a single cell in the darkness of a virgin's womb. This is the mystery before which every attempt at explanation falters: not that God made a man, but that God became a man while never ceasing to be God. The Word did not clothe Himself in flesh as a man puts on a coat; He took flesh as His own, joining it to His divine person in a union that death itself could not dissolve. Section 1 drew our gaze upward into the eternal counsel where the Father chose and ordained the Son as Mediator. There we stood at the edge of eternity and watched the pactum salutis unfold within the Godhead. Now our gaze drops to a specific place on the map and a specific moment on the calendar. The eternal purpose becomes an historical event. The Son who was chosen before the foundation of the world enters the world He helped to create, not in the fullness of His glory, which would have consumed the planet, but in the fragility of human flesh, born of a woman, born under the law. If the incarnation is not true, if Jesus Christ is not both fully God and fully man in one person, then there is no Mediator at all, and we are still in our sins. But if it is true — and the church has confessed it through every century of her pilgrimage, often at the cost of her blood — then the distance between God and man has been bridged from God's side by God Himself, and the bridge is a Person, Jesus Christ.

Scripture Foundation

The Confession does not construct its Christology from philosophical abstraction but from the apostolic witness, and the apostolic witness begins with a declaration that stands apart in religious literature. In John 1:1, 14, the apostle John writes: "In the beginning was the Word, and the Word was with God, and the Word was God." Three clauses, each profound in its own way. The Word was, existing before all beginnings, an eternal ēn that no aorist can capture. The Word was with God, distinct in person, facing the Father in eternal communion, pros ton theon. And the Word was God, not a god, not divine in some diminished sense, but theos, sharing the very being of the Father, as the Nicene Creed would later crystallize it: homoousios tō patri, of one substance with the Father. Upon this triple foundation John erects his central conclusion: "And the Word was made flesh, and dwelt among us." The Greek is ho logos sarx egeneto. Not "the Word appeared as flesh," not "the Word inhabited flesh," but "the Word became flesh." Sarx is John's direct word for human nature in its frailty and mortality, not the dignified sōma (body) that Paul often uses, but the word that carries associations with weakness and dust. The eternal Word entered fully into the condition of created humanity, subject to hunger and thirst and weariness and grief and death. Paul takes up the same mystery in a passage that many scholars believe to be an early Christian hymn. In Philippians 2:5-8, he writes of Christ Jesus "who, being in the form of God, thought it not robbery to be equal with God: but made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: and being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross." "Being in the form of God" — en morphē theou hyparchōn — describes not a changeable appearance but the essential nature of deity. The participle hyparchōn points to a continuing state; He remained what He was while becoming what He was not. The phrase "made himself of no reputation" translates heauton ekenōsen, literally "He emptied Himself." Christ emptied Himself not by subtracting His deity but by adding humanity, by "taking the form of a servant." The emptying was a veiling of divine glory, a voluntary submission to the conditions of creaturely existence. The one who was equal with God became obedient to death, not subtraction but addition, the addition of a human nature to the divine person with all the limitations that genuine humanity entails. The author of Hebrews draws out the pastoral logic of the incarnation with clarity. In Hebrews 2:14-18, we read: "Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil; and deliver them who through fear of death were all their lifetime subject to bondage. For verily he took not on him the nature of angels; but he took on him the seed of Abraham. Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people. For in that he himself hath suffered being tempted, he is able to succour them that are tempted." The Mediator had to share the nature of those He came to redeem. Adam's race required an Adamic Mediator — one who was bone of our bone and flesh of our flesh, tempted in all points as we are, yet without sin. Only by becoming what we are could He die the death we deserved and break the power of the one who held us in bondage through the fear of death. And only by suffering temptation in a real human nature could He become the merciful High Priest who understands our weakness from the inside. The incarnation is not a theological ornament; it is the indispensable condition of our salvation. One further passage completes the apostolic witness. In 1 Timothy 3:16, Paul encapsulates the gospel in what was likely an early creedal formulation: "And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory." The word "mystery" — mystērion — is crucial. Paul does not mean a puzzle to be solved but a truth that could never have been discovered by human reason but has now been revealed by God. No philosopher, scanning the heavens or plumbing the depths of his own mind, could have conceived that the Creator would enter His own creation as a creature. This is not the conclusion of a syllogism but the disclosure of God, and it remains a mystery even after it is disclosed. The church does not explain the incarnation; she confesses it, adores it, and guards its boundaries. "God was manifest in the flesh" — the very conjunction of subject and predicate should stop the breath. God, the uncreated, the infinite, the One who inhabits eternity, manifest in the frailty of a body that could hunger and weep and bleed and die. If this does not fill you with astonishment, you have not begun to understand what you are saying when you call Jesus Lord.

What the Divines Meant

When the Westminster Assembly composed this section in the mid-1640s, they were not writing on a blank slate. Fifteen centuries of Christological controversy stood behind every phrase, and their language was forged in the fires of those controversies. The Divines wanted their confession to be catholic in the best sense, consistent with the ancient creeds, particularly the Definition of Chalcedon (AD 451), while also addressing errors that had reappeared in their own day under new names. The first error was Arianism, revived in the sixteenth century by Faustus Socinus and his followers. The original Arius had taught that the Son was a created being, the first and highest of God's creatures, but not eternal and not of the same substance as the Father. Against this, the Confession declares that the Son is "very and eternal God, of one substance and equal with the Father." The phrase "very God" translates the Latin vere Deus, the language of Chalcedon: the Son is not God in a diminished sense but truly, essentially, and fully God. "Of one substance" — homoousios — was the word over which Nicaea fought its defining battle in AD 325. Athanasius saw what Arius could not: if Christ is not truly God, then He cannot truly save. Only God can reconcile men to God. The blood of a creature, however exalted, cannot satisfy infinite justice. The one who took flesh was no angel, no demigod, no emanation, but the eternal Son, co-equal and co-essential with the Father. The second cluster of errors concerned the manner in which deity and humanity were united in Christ. Apollinarius of Laodicea taught that Christ possessed a human body but not a human rational soul; the divine Logos replaced the human mind. Gregory of Nazianzus answered him with the principle that became a touchstone of orthodox Christology: "What has not been assumed has not been healed." If Christ did not assume a full human nature, body, soul, mind, and will, then the unassumed parts remain unhealed. The Confession answers by insisting that Christ took "man's nature, with all the essential properties and common infirmities thereof, yet without sin." He assumed everything that belongs to genuine humanity: a rational soul, intellectual and volitional capacities, the full range of human emotion from the joy of a wedding feast to the anguish of Gethsemane. The one thing He did not assume was sin, not because sin is essential to human nature, but because it is an alien intruder, a corruption of the nature God created good. Christ assumed the nature of Adam before the fall, though He bore the fall's consequences in His body and suffered the curse for His people. Nestorius, the fifth-century patriarch of Constantinople, taught a separation between Christ's two natures so sharp that it divided the one Christ into two persons: the divine Son and the human Jesus, conjoined by a moral union. He refused to call Mary theotokos (God-bearer), preferring Christotokos, because he could not conceive that the eternal God could be born of a woman. The Council of Ephesus (AD 431) condemned this under the leadership of Cyril of Alexandria, who insisted that the subject of all Christ's actions, divine and human, is the one divine Person. It is the eternal Son who is born of Mary, who hungers and weeps, who dies on the cross. The Confession follows Cyril precisely: the two natures "were inseparably joined together in one person." The person — the hypostasis, the acting subject — is singular. The natures are two. Both remain whole, perfect, and distinct. This is the communicatio idiomatum, the communication of attributes: we can rightly say that God purchased the church with His own blood (Acts 20:28), because the attributes of both natures belong to the one Person. The third error, Eutychianism, was the opposite of Nestorianism. Eutyches so emphasized Christ's unity that he dissolved the two natures into a single new nature, a tertium quid that was neither fully divine nor fully human. The Council of Chalcedon answered with the four great negative adverbs that the Confession echoes: "without conversion, without composition, without confusion." The divine nature was not changed into the human; the human was not changed into the divine; the two were not mixed to form a third thing. Each nature retains its essential properties: the divine remains infinite, omnipotent, and impassible; the human remains finite, limited, and passible. The miracle of the incarnation is not that the two natures blended but that they united without blending. These six words summarize what the ancient church took four ecumenical councils to articulate. The Divines knew that a single misplaced syllable could unravel the whole gospel. They chose their words with the care of surgeons operating on the heart of the faith. Robert Shaw, in his exposition of the Confession, draws particular attention to "conceived by the power of the Holy Ghost in the womb of the Virgin Mary, of her substance." This clause establishes both the supernatural character of Christ's conception and the genuineness of His human nature. The conception was supernatural, not because a new person was created, the Person of the Son existed from eternity, but because a human nature was produced in the virgin's womb by the immediate power of the Holy Spirit, without a human father. And because this human nature was formed "of her substance," Christ was truly the seed of the woman, truly the son of David according to the flesh, genealogically and biologically connected to the race He came to redeem. He did not descend from heaven with a body already formed, as Gnostics taught. He took His humanity from Mary. The virgin birth is not mythological embellishment but theological necessity: the means by which the eternal Son assumed a true and sinless human nature from the line of Adam.

Theological Depth

The incarnation has drawn from the church's greatest minds not only precise definition but profound adoration. Athanasius of Alexandria, in his treatise On the Incarnation, written when he was barely in his twenties, presses the question of why the incarnation was necessary. God could have forgiven sin by a mere word, as He created the world by a word. Why the humiliation, the manger, the cross? Athanasius answers by tying creation and redemption into a single divine purpose. Man was made in the image of God, destined for participation in the divine life, for incorruption and immortality. When man sinned, he turned from life toward death, and corruption entered his being. A mere word of forgiveness would have left man in his corruption. What was needed was the re-creation of human nature from within, the infusion of divine life into the dying organism of humanity. This could only be accomplished if the Word, through whom all things were made, entered creation and assumed the nature that had fallen, uniting it to Himself and healing it at its root. Athanasius employs a striking image: as when a great king enters a city and takes up residence in one of its houses, the whole city is honored and protected, so the King of creation took a body from our race, and by His presence death itself has been overthrown. The incarnation is the restoration of the original purpose of creation, the renewal of God's image in man through the presence of the Image Himself. Gregory of Nazianzus gave the church the definitive formula for understanding what is at stake in Christ's full humanity. In his Theological Orations, he states his famous principle: "That which He has not assumed He has not healed; but that which is united to His Godhead is also saved." If Christ lacked a human mind, the human mind is not saved. If Christ had no human will, the human will remains unredeemed. Salvation is not a legal fiction by which God pretends we are righteous while leaving our actual humanity untouched. It is the healing and transformation of the whole person, body, soul, mind, and will, through union with the one in whom the fullness of deity dwells bodily. Christ wept, and human sorrow was sanctified. Christ was tempted, and human resistance to sin was empowered. Christ died, and human death was defeated from within. Christ rose, and human nature was lifted to the right hand of God. There is no corner of our humanity that Christ has not touched and healed, because there is no corner He did not assume. John Owen, whose Christologia represents the high-water mark of Puritan reflection on Christ's person, directs our attention to the wonder of the union itself. The human nature of Christ exists only because the Son willed to assume it; it has no independent personhood but subsists in the person of the Son. This means that every human experience of Christ — every hunger, every tear, every prayer — is experienced by the eternal Son of God. When you are hungry, Christ understands, for He has been hungry. When you are weary, Christ understands, for He sat wearied by Jacob's well. When you are tempted, Christ understands, for He endured the full assault of the tempter in a human nature that felt the full force of every temptation. Your Mediator is not a distant deity dispensing grace from afar; He is a sympathetic High Priest who has passed through every trial you face, sin alone excepted. Owen writes that "the glory of the person of Christ is the great foundation of the faith, obedience, and consolation of the church." A defective Christology produces a defective Christianity. A robust Christology, grounded in the careful formulations of Scripture and creed, produces a robust faith. Geerhardus Vos, the Princeton biblical theologian, offers a final insight into the phrase "when the fulness of time was come." The Greek is to plērōma tou chronou, not merely the right time, but the time that had been filled up to its appointed measure. Vos observes that the incarnation occurred at a precise intersection of divine preparation. The world had been providentially readied: a common language, a common political framework, a messianic expectation spread far beyond Israel. But more profoundly, the history of Israel had reached its appointed culmination. The covenant with Abraham, the law through Moses, the kingdom under David, the exile, the return — all of it had been filling up the measure of time, accumulating the types and shadows that Christ would fulfill. When Paul writes that "when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law" (Galatians 4:4), he describes not a divine response to a human opportunity but the execution of a divine timetable set from eternity. Every prophecy, every sacrifice, every feast: all of it was waiting for the one who would come when the time was full.

Puritan Application

First, let the incarnation teach you to measure the love of God. We are accustomed to measuring divine love by the cross, and rightly so. But the incarnation itself, even before the cross, is a demonstration of love that defies comprehension. The eternal Son did not die for us alone; He lived for us, and before He lived for us, He became one of us. He exchanged the adoration of angels for the misunderstanding of His own family. He left the throne of heaven for a stable in Bethlehem. He laid aside the glory He had with the Father before the world was and consented to be wrapped in strips of cloth by a teenage mother too poor to afford a proper room. If you would know the love of God, do not only look at the cross. Look at the cradle. Look at the thirty years of obscurity in Nazareth, the eternal Son learning the trade of Joseph, calloused hands and sawdust and the slow patience of ordinary human life. The God who needed nothing became a baby who needed everything. This is love that surpasses knowledge. Second, let the two natures of Christ be a deep foundation for your assurance. Your salvation does not rest on a Christ who is only God, for God who is not man cannot represent man. It does not rest on a Christ who is only man, for man who is not God cannot bear infinite wrath. Your salvation rests on a Christ who is both: true God, able to satisfy divine justice to the full, and true man, able to stand in your place as your federal head. The two natures are the two pillars on which your entire hope is suspended. When your conscience accuses, remember that your Mediator is God, and His righteousness is infinite, His blood of infinite value. When you feel your weakness, your body aching and your spirit flagging, remember that your Mediator is man, and He understands weakness from the inside, having worn your flesh and borne your infirmities, sin alone excepted. There is no distance between you and Him that His incarnation has not bridged. Third, let the sinlessness of Christ give you hope in your struggle against sin. Christ assumed all the essential properties of human nature, including hunger, thirst, weariness, sorrow, the capacity to suffer and die, but He did not assume sin. He was tempted in all points as we are, yet without sin. His sinlessness was not because His temptations were unreal; they were more real than ours, because temptation increases in proportion to holiness. A violin string that is never bowed produces no resistance; the holy soul of Christ, struck by every foul suggestion of the enemy, vibrated with a loathing we can barely imagine. His temptations were real, His resistance was real, His victory was real — and it was a human victory, achieved in a human nature sustained by the Spirit, not by calling on resources of deity unavailable to us. The same Spirit who sustained Christ in the wilderness dwells in you. The same Word Christ wielded against the tempter is in your hands. And when you fall, your hope is not that you will achieve sinlessness in this life but that Christ has achieved it for you, His perfect obedience reckoned as yours through faith. Fourth, let the virgin birth teach you that salvation is entirely of God. The conception of Christ by the Holy Ghost in the womb of the Virgin Mary is a sign pointing to a theological reality. As no human father was involved in the conception, so human effort and merit are not involved in the new birth. The same Spirit who formed Christ's nature in Mary's womb creates new life in the dead soul. The virgin birth is a parable in flesh of the doctrine of grace. Just as Mary did not cooperate with the Spirit to produce the incarnation — she received it, but she did not contribute to the creative act — so the sinner does not cooperate with the Spirit to produce regeneration. The Spirit blows where He wills. The new birth is monergistic: God alone acts to bring the dead to life. Rest in this: your salvation, from its eternal purpose to its final consummation, is God's work from first to last. Fifth, let the union of two natures in one person teach you the dignity of your own humanity. There is a strain of piety that regards the body as a prison and the material world as a distraction. The incarnation judges this as sub-Christian. The eternal Son did not despise the body; He took one. He did not regard matter as beneath His dignity; He became matter. He will remain incarnate for all eternity. There is a man, a real embodied glorified man, seated at the right hand of God. Your body is not a temporary vehicle you will discard; it is destined for resurrection and glorification. The incarnation teaches you to honor the body, to honor the ordinary — the work of human hands, the life of human families, the sorrows and joys of human existence — because Christ sanctified all of it by His participation. You do not need to escape your humanity to be spiritual. You need to bring your humanity, in all its weakness, to the one who made it His own. He is not asking you to be more than human. He is asking you to be fully human, as He was, in dependence on the Father, empowered by the Spirit, living for Him who for your sake became what you are so that you might become what He is.

Prayer

O Lord Jesus Christ, eternal Son of the Father, very God of very God, who didst not disdain the Virgin's womb but didst take our nature into Thyself and make it Thine own, we confess that we cannot comprehend this mystery. That Thou, the Word through whom the worlds were made, shouldst become flesh and dwell among us: this is too wonderful for us. Yet Thou hast revealed it, and we receive it with adoring faith. We bless Thee that Thou didst not come in the fullness of Thy majesty, which would have consumed us, but didst veil Thy glory in the weakness of infancy and the humility of a servant's form. Thou who wert rich beyond all splendor didst for our sakes become poor, that we through Thy poverty might become rich. We thank Thee that Thou didst take upon Thee not the nature of angels but the seed of Abraham, becoming bone of our bone and flesh of our flesh, tempted in all points as we are, yet without sin. We thank Thee that Thou didst not shrink from our infirmities: our hunger, our weariness, our sorrow, our tears, our death, but didst bear them all in love, sanctifying every stage of human life from conception to the grave. Because Thou hast worn our flesh, we know our flesh is not beneath Thy notice. Because Thou hast wept our tears, we know our tears are precious in Thy sight. Because Thou hast tasted our death, we know death has been swallowed up in victory. O Thou who art very God and very man in one Person forever, be to us the Mediator we need. When we are tempted to despair, remind us that Thou art God, and Thy power is infinite. When we are tempted to think that no one understands, remind us that Thou art man, and Thou hast walked our road to its bitter end. Thou art the bridge between heaven and earth, and there is no other. Be Thou our wisdom, our righteousness, our sanctification, and our redemption. Grant us a deepening wonder at the mystery of Thy person. Guard us from a Christology that is merely correct in its formulas but cold in its affections. May we never grow casual about the cradle of Bethlehem or the cross of Calvary or the empty tomb or the throne at the Father's right hand. And bring us at last to that day when faith gives way to sight, and we shall see Thee as Thou art, no longer veiled in humility but radiant in glory, yet still wearing our nature, still the same Jesus who loved us and gave Thyself for us. O Holy Spirit, who didst overshadow the Virgin and form the human nature of our Lord in her womb, overshadow us now. Form Christ in us. Conform us to His image from one degree of glory to another, until the day when we shall be like Him, for we shall see Him as He is. To the only wise God our Saviour, Father, Son, and Holy Spirit, be glory and majesty, dominion and power, both now and ever. Amen.