In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. . . . And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth. (John 1:1–2, 14, emphasis added)

The words that open the gospel of John are among the most astounding and wondrous words in all Holy Scripture. A Christian could spend his entire life meditating on the meaning of these sentences, and at the end of his life he will at most have only scratched the surface. The Apostle John speaks here of one of the most profound mysteries of the Christian faith, the incarnation of the eternal Son of God, the One who was in the beginning with God, the One who was with God, the One who is God.

But what does it mean to say that the Word, the Son of God, became flesh? Does it mean that God transformed into a man? Does it mean that God’s nature and man’s nature were blended somehow to create a new hybrid nature? Does it mean that God changed?


The question is important because Scripture teaches and orthodox Christians have always taught that God’s nature is, by definition, immutable. Article 1 of the Belgic Confession, for example, states:

We all believe with the heart, and confess with the mouth, that there is one only simple and spiritual Being, which we call God; and that he is eternal, incomprehensible invisible, immutable, infinite, almighty, perfectly wise, just, good, and the overflowing fountain of all good. (Emphasis added)

The Westminster Confession of Faith, likewise, states:

There is but one only, living, and true God: who is infinite in being and perfection, a most pure spirit, invisible, without body, parts, or passions, immutable, immense, eternal, incomprehensible, almighty, most wise, most holy, most free, most absolute, working all things according to the counsel of His own immutable and most righteous will, for His own glory; most loving, gracious, merciful, long-suffering, abundant in goodness and truth, forgiving iniquity, transgression, and sin; the rewarder of them that diligently seek Him; and withal, most just and terrible in His judgments, hating all sin, and who will by no means clear the guilt. (WCF 2.1, emphasis added)

Orthodox Christians have always taught that God is immutable because that is what God has revealed about His nature in Scripture. He proclaims through the prophet Malachi, for example, “I the LORD do not change” (Mal. 3:6). In the New Testament, we see the same. James, for example, writes: “Every good gift and every perfect gift is from above, coming down from the Father of lights, with whom there is no variation or shadow due to change” (James 1:17).

The Apostle John speaks here of one of the most profound mysteries of the Christian faith, the incarnation of the eternal Son of God.

The section of the Westminster Confession cited above expresses how God’s immutability defines His other attributes by noting that God’s will is unchanging. The same is true of God’s other attributes. Because God is His attributes, His perfection is immutable. His power is immutable. His knowledge is immutable. His goodness is immutable. His glory is immutable. His love is immutable. His truth is immutable. For God to change in His essence and attributes would be for God to cease to be God.

We have to take care when discussing divine immutability because the word “immutability” is a negation. When we say that God is immutable, we are saying that He is not mutable. His essence and attributes do not change. When we say that God is immutable, we are denying of the Creator something that is true only of creatures. Only created beings are mutable. Only created beings are changeable. In other words, when we predicate immutability of God, we are not saying what the divine nature is. We are saying what it is not. We are saying that the divine being is not the same kind of being that creaturely being is.

At the same time, however, we have to make sure that we avoid reading creaturely kinds of immutability into the concept of divine immutability. As Michael Dodds has helpfully observed, some created things like granite, for example, have a limited kind of immutability (The Unchanging God of Love, p. 15). It is not absolute because over time, wind and rain and other forces will change even the hardest piece of stone, but a piece of granite has a relative kind of immutability. Relative to living creatures, it doesn’t change. It is a static, immobile thing. When we say that God is immutable, we are not predicating this kind of creaturely “immutability” to Him. We are not affirming that God is a static, immobile, inert piece of granite. It is true that God is unchangeable, but it is also true that God is love. He is unchangeable love. God is immutable, but He is also “most loving, gracious, merciful, long-suffering, abundant in goodness and truth, forgiving iniquity, transgression, and sin.”

We also have to remember that God is triune. This means that we affirm that God the Father eternally begets the Son, and the Holy Spirit eternally proceeds from the Father and the Son. This eternal begetting and eternal spiration clearly reveal that God is not immutable in the way that a piece of dead granite is relatively immutable. The Creator differs from His creation. God’s eternal generation and eternal spiration are an immutable eternal generation and an immutable eternal spiration, just as God’s eternal willing, eternal knowing, and eternal loving are an immutable willing, immutable knowing, and immutable loving.


In recent decades, many people, including professing evangelical and Reformed theologians, have radically redefined or outright rejected the classical theism expressed in writings such as the Belgic Confession and Westminster Confession and taught by theologians from Athanasius of Alexandria and Augustine of Hippo to Francis Turretin and Charles Hodge. One of the reasons that is often given for such a move is the alleged incompatibility of the classical theist doctrine of immutability with the incarnation of the Son. If we are to affirm the incarnation, it is argued, we are required to affirm that God changed. If God changed at the time of the incarnation, then it cannot be true that God is immutable.

The divine being is not the same kind of being that creaturely being is.

The classical Trinitarian theism taught by orthodox Christians, on the other hand, has always affirmed both God’s immutability and the incarnation of the Son of God. In fact, every discussion of the incarnation by orthodox Christians assumed the truth of God’s immutability. This assumption finds its way into earliest orthodox creeds of the church. The Nicene Creed of AD 325, for example, includes several condemnations at the end. Among the Arian doctrines that were condemned in the Nicene Creed is the idea that “the Son of God is subject to change or alteration.” Why was this idea condemned? Because the Son is homoousios with the Father. The attribute of immutability defines the very nature of both the Father and the Son. Contemporary evangelical and Reformed theologians who are affirming that the Son did change in the incarnation ought to consider this for a moment. Not only are some of these men rejecting denominational confessions of faith they swore before God to uphold in vows made to their churches and institutions of education, they are also attacking Nicene Trinitarianism. They are placing themselves among the ranks of the arch-heretics of church history, enemies of Christ and of His people.

As the Christological debates developed during the fifth century, orthodox theologians continued to affirm that God did not change in the incarnation. Cyril of Alexandria, for example, wrote the following in his Second Letter to Nestorius:

We too ought to follow these words and these teachings and consider what is meant by saying that the Word from God took flesh and became man. For we do not say that the nature of the Word was changed and became flesh, nor that he was turned into a whole man made of body and soul. Rather do we claim that the Word in an unspeakable, inconceivable manner united to himself hypostatically flesh enlivened by a rational soul, and so became man and was called son of man, not by God’s will alone or good pleasure, nor by the assumption of a person alone. (Emphasis added)

The Council of Chalcedon would later list several of Cyril’s letters, including this one, along with the Tome of Leo as statements of orthodox Christology to which Christians should go for a fuller explanation of biblical doctrine.

God’s eternal generation and eternal spiration are an immutable eternal generation and an immutable eternal spiration.

The Council of Chalcedon itself affirmed in the Definition of Chalcedon that God did not change in the hypostatic union. We read the following in the penultimate paragraph:

So, following the saintly fathers, we all with one voice teach the confession of one and the same Son, our Lord Jesus Christ: the same perfect in divinity and perfect in humanity, the same truly God and truly man, of a rational soul and a body; consubstantial with the Father as regards his divinity, and the same consubstantial with us as regards his humanity; like us in all respects except for sin; begotten before the ages from the Father as regards his divinity, and in the last days the same for us and for our salvation from Mary, the virgin God-bearer as regards his humanity; one and the same Christ, Son, Lord, only-begotten, acknowledged in two natures which undergo no confusion, no change, no division, no separation; at no point was the difference between the natures taken away through the union, but rather the property of both natures is preserved and comes together into a single person and a single subsistent being; he is not parted or divided into two persons, but is one and the same only-begotten Son, God, Word, Lord Jesus Christ, just as the prophets taught from the beginning about him, and as the Lord Jesus Christ himself instructed us, and as the creed of the fathers handed it down to us. (Emphasis added)

The immutable divine nature did not change into something else because it could not. Human nature is not immutable even in a relative creaturely sense, but even it was not changed into something other than human nature in the hypostatic union. The properties of both natures were preserved. The divine nature retained its attribute of immutability, and the human nature united to the divine nature was mutable. Those who affirm that God did change in the incarnation are rejecting both the teaching of Nicaea and Chalcedon on the most fundamental doctrines of the Christian faith, the doctrine of God and the doctrine of Christ.

The Second Council of Constantinople in AD 553 reaffirmed the doctrine of the earlier councils in its seventh anathema when it stated:

If anyone, when speaking about the two natures, does not confess a belief in our one Lord Jesus Christ, understood in both his divinity and his humanity, so as by this to signify a difference of natures of which an ineffable union has been made without confusion, in which neither the nature of the Word was changed into the nature of human flesh, nor was the nature of human flesh changed into that of the Word (each remained what it was by nature, even after the union, as this had been made in respect of subsistence).

The Reformed theologians and confessions maintained Nicene and Chalcedonian orthodoxy on this point. They continued to uphold both biblical doctrines: divine immutability and the incarnation. John Calvin, for example, writes: “When it is said that the Word was made flesh, we must not understand it as if he were either changed into flesh, or confusedly intermingled with flesh, but that he made choice of the Virgin’s womb as a temple in which he might dwell. He who was the Son of God became the Son of man, not by confusion of substance, but by unity of person. For we maintain, that the divinity was so conjoined and united with the humanity, that the entire properties of each nature remain entire, and yet the two natures constitute only one Christ” (Institutes of the Christian Religion, 2.14.1, emphasis added).

The Reformed scholastic Francis Turretin states clearly, “God was not changed by the incarnation” (Institutes of Elenctic Theology, 1:205). The great Puritan theologian Stephen Charnock concurs: “There was no change in the Divine nature of the Son, when he assumed human nature” (The Existence and Attributes of God, 1:339). The Westminster Confession of Faith summarizes this point of Chalcedonian Christology, affirming that the two natures “were inseparably joined together in one person, without conversion, composition, or confusion” (8:2, emphasis added).

Quite clearly, the orthodox Christian answer to the question “Did God change in the incarnation?” is a resounding “No!”

Editor’s Note: This post was originally published on July 21, 2021.

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