For centuries, the Eastern Orthodox churches have made the doctrine of deification, or theosis, central to their theology and Divine Liturgy. However, recently, Catholic theologians too have been intrigued with the idea of deification framed in a Western context. In fact, the 1994 publication of the Catechism of the Catholic Church makes reference to some classic patristic notions at the root of deification. For example, in the article discussing original sin, the Catechism alludes to man’s being “destined to be fully divinized by God in glory.” Furthermore, in its article on the Incarnation (§460), after citing the words of Peter mentioned above, the Catechism states, “For the Son of God became man so that we might become God.” However, the Catechism does not explain what this means at all nor does it supply any definition. It simply cites patristic fathers, most prominently St. Irenaeus and St. Maximus the Confessor.
This doctrine of deification needs to be articulated. Not only is the term “deification” itself found nowhere in scripture, but it seems somewhat heretical to believe in some way we as human beings are destined to be “like God.” My aim in this essay is to give a synthetic account of deification in Christ as the full outworking of grace in the Christian life. The topic of grace in general is far beyond the scope of this essay, therefore, this will not be a treatise on grace, but rather an account of grace as it relates to our deification in Christ through the Spirit. Ultimately, my purpose is to offer a theological account of deification so that we may grasp its essential elements and understand how deification offers an integrated account of the Christian understanding of salvation. As previously mentioned, the Eastern church has made the doctrine of deification central to its liturgy for centuries, however, the doctrine of deification is not the doctrine of the Eastern church alone. Rather, deification concerns the basic economy of God in Christ through the Spirit that is at the patristic root of both the Eastern and Western traditions. I am in no way denying that real and distinct differences exist between the traditions, but by proposing that there is a core account of deification common to the traditions, I am simply seeking a common base upon which our “catholic” faith can develop.
When the doctrine of deification is discussed, there are certain questions that constantly beset the doctrine. The question that we will discuss in this essay is the following: Doesn’t the doctrine of deification, by virtue of its elevated and exaggerated rhetoric, effectively compromise the fundamental distinction between God and the created order, and so lead explicitly or implicitly to a form of pantheism?
The Grace Formula of Exchange
The best place to begin a synthesis of deification is what is commonly called the “formula of exchange.” In essence, this formula asserts that the Son of God became what we are so that we could become what he is. The earliest examples of this formula are found in the writings of St. Irenaeus, who is considered the originator of this way of summarizing our redemption.
- There was no other way for us to receive incorruptibility and immortality than to be united to incorruptibility and immortality. But how could we be united to incorruptibility and immortality without incorruptibility and immortality first becoming what we are, the perishable putting on imperishability, the mortal putting on immortality, so that we might receive adoption as sons. In His immeasurable love, He became what we are in order to make us what He is.
This Irenaean principle is the fundamental basis for the doctrine of deification. In the East, St. Maximus the Confessor expresses the content of this formula: “For through the perfect recovery of nature you are distinguished by grace alone and are destined by the power that derives from this to be proved a god in the same degree as he who is God by nature partook of our weakness when he became incarnate.” Centuries later, in the West, Thomas Aquinas shows that this formula is alive and well:
- The only-begotten Son of God, wishing to make us sharers in his divine nature, assumed our nature, so that made man he might make gods. For the human mind and will could never imagine, understand, or ask that God become man, and that man become God and a sharer in the divine nature. But he has done this in us by his power, and it was accomplished in the Incarnation of his Son: “That you may become partakers of the divine nature.” (2 Peter 1:4)
Joseph Ratzinger provides us with a contemporary restatement of this exchange at the heart of the Gospel. He states, “This exchange consists of God taking our human existence on himself in order to bestow his divine existence in us, of his choosing our nothingness in order to give his plentitude.”
It is crucial to recognize that the formula of exchange, in the variety of its expressions, is a shorthand way to sum up all that God has done in Christ for the human race. It is a statement that intends to display at once the marvelous condescension of Christ and the wonderful destiny to which he has called us in himself. But this still begs this question, what does this mean? Is it just an invention of the Church Fathers, or does it have sound biblical standing? If we as modern believers are to make sense of the formula of exchange, we need to investigate its biblical foundation.
Biblical Foundation for the Doctrine of Deification
During his discussion of the Law and Christ, St. Paul writes to the Galatians, “But when the fullness of time had come, God sent forth His Son, born from woman, born under Law, to redeem those under the Law, so that we might receive adoption as sons” (Gal 4:4-5). The Fathers read this text as summing up Christ’s Incarnation and redemptive death. The crucial point here is the connection between the Son (νίος) who is sent and the consequence of his being sent, our adoption as sons (νίούθεσια). What was the purpose of God’s redeeming work in Christ? To extend to us a share in his own sonship, or as St. Irenaeus says, “He became the Son of man to accustom man.”
In his letter to the Romans, St. Paul introduces the role of the Holy Spirit in bringing about our sonship in Christ. In this letter, St. Paul shows the essential connection between the gift of the indwelling of the Holy Spirit and our sonship in Christ. This notion is reinforced in 2 Corinthians 3:18, where St. Paul speaks about our being transformed into his “image” from one degree of glory to another. How has Christ enriched us? By assuming our humanity and redeeming us in and through that humanity, he has given us adoption as sons of God through the Holy Spirit, for the purpose of transforming us to be made progressively into the image of the Son himself, imago Christi.
If these texts provide the scriptural foundation for the formula of exchange, it is the biblical notion of Christ as the New Adam that provides the wider theological framework. Christ as the one who overcomes Adam’s sins and the effects that it has, is now the firstfruits of a new humanity that is cleansed from sin and capable of bearing the life of the Holy Spirit. St. Paul clearly states, “Just as we have been born the image of man of dust, we shall also bear the image of the man of heaven” (1 Cor. 15:49). This is precisely how Irenaeus reads the biblical story of our salvation. Commenting on Ephesians 1:10, Irenaeus states:
- When he became incarnate, and was made man, he recapitulated in himself the long line of human beings, and furnished us, in a brief, comprehensive manner, with salvation; so that what we had lost in Adam; namely, to be according to the image and likeness of God, that we might recover in Christ Jesus.
These biblical texts in conjunction with Christ as the New Adam and our transformation into his image provide the primary biblical foundation and framework for the formula that Christ became as we are so that we might become as he is.
Receiving the Divine Life
Our synthesis thus far has attempted to give an account of redeemed humanity in Christ through an exchange of grace. The doctrine of deification is, therefore, centered in Christ himself. It is because of his assumption of our humanity, and his redemption of that same humanity, that we are enabled to participate in the divine life as adoptive sons, having an indwelling of the Trinity in us. Logically, the next question would be, how and by what means does God come to dwell within us? How does this occur? The consistent position by the Church Fathers, both East and West, is that God comes to dwell in us through baptism and the Eucharist.
The Fathers give ample testimony to baptism and the gift of the indwelling Spirit as the beginning of our divine filiation and deification. For example Leo the Great exhorts us not to squander our divine sonship and participation in the divine nature gained through baptism. He states:
- Realize, O Christian, your dignity. Once made “a partaker of the divine nature,” do not return to your former baseness by a life unworthy [of that dignity] …Through the sacrament of baptism your were made a “temple of the Holy Spirit.” Do not drive away such a dweller by your wicked actions and subject yourself again to servitude under the devil.
St. Maximus the Confessor links water baptism as a means by which the Holy Spirit causes us to become “gods by grace”:
- The Holy Spirit is active in [baptism by water]… As eater he purifies the defilement of the flesh, and as the Spirit he cleanses the stain of the soul. As the Holy Spirit he establishes as preliminary the way of the virtues…[to] make a person God by grace, radiating on him the divine characteristics of virtue.
Thomas Aquinas uses the metaphor of food and drink to speak of our divine inebriation through the Eucharist. Aquinas says, “For the food is not changed into the one who eats it, but it turns the one who takes it into itself…and so this is a food capable of making man divine and inebriating him with divinity.”
The immersion of the body in the water of baptism, the anointing of the body with oil, and the feeding of the body with the body and blood of Christ signify the transformation of the whole of human nature, body and soul.
Partakers of the Divine Nature
We have now synthesized in some detail the meaning of deification according to the “formula of exchange” and how we have become “sons” and “gods” by receiving new life through the indwelling of God by means of the sacraments of initiation. We now can address the question: Does the doctrine of deification, by means of its elevating man to being a deified being, compromise the fundamental distinction between God and man. In other words, doesn’t the notion of deification play into the hands of those religious movements that claim, “you yourself are God,” and so refuse to recognize any sovereign and transcendent God deserving of our worship and obedience? The short answer to these question is no. Properly understood, the Christian doctrine of deification not only maintains the distinction between God and the created order, but is based on it.
The primary statement in the Christian tradition that upholds this difference takes some form of the saying, “we become gods, not by nature, but by grace.” Augustine is especially eloquent on this point. He consistently states that our share in the divine life, by grace and not by nature, is distinct from Christ’s natural divinity. He clearly says, “It is evident, then, as he has called men gods, that they deified by his grace, not born of his substance… If we have been made sons of God, we have also been made gods: but this is the effect of grace adopting, not of nature generating.”
Aquinas speaks in nearly identical language about our destiny as “gods by grace,” linking this claim to the central biblical texts on deification. Explaining how Christ loved his disciples as the Father loved him, Thomas says:
- For [Christ] did not love them to the point of their being gods by nature, nor to the point that they would be united to God so as to form one person with him, But he did love them up to a similar point: he loved them to the extent that they would be gods but their participation in grace…”He has granted to us precious and very great promises, that through these you may become partakers of the divine nature” (1 Pet 1:4).
Deification does not remove us from the creaturely limitations of human nature; rather, it is the glorification and transformation of our nature by a grace participation in God. This participation is the primary means by which the Fathers sought to describe how we are “gods, not by nature, but by grace.” Christ partook our nature and became fully what we are, so that we might partake of the divine nature and become, by grace and participation, what he is by nature. Stated another way, Christ, being consubstantial with the Father, became fully human, and through the Incarnation, become consubstantial with us in our nature, so that we might become partakers in his nature, that being his divine nature. Be we never become consubstantial with the Father as he is; rather, we participate by grace in the divine nature of the communion of Divine Persons. This is what it means to become “gods by grace.”
In short, the concept of participation enables us to grasp how we are genuinely related to God and can partake of his life, without jeopardizing the infinite difference that distinguishes the uncreated Trinity from all creatures.
Conclusion: The Beauty of Deification
The foundation for understanding deification is the redemption of our inhumanity in Christ himself through the “graced exchange” at the heart of the Gospel. By means of the assumption of human nature by Christ, and the transformation of that nature in himself, we are called and enabled to participate as creatures in the divine nature. The Son of God became the Son of Man, so that sons and daughters of men might become sons and daughters of God. The Incarnation, the passion, the crucifixion, and the resurrection are at the center of Christian deification.
That deification does not mean an ontological promotion to something other than we are. We do not become God as God is, but we come to participate in his divine life and power. Our nature is elevated and glorified, but as deified we remain creatures and human beings completely dependent on God as our source. Deification is the honored status rejected by Adam and attained by Christ, the New Adam.
Finally, the doctrine of deification enhances the doctrine of the Incarnation, of the Trinity, and the divine economy of the Father in Christ through Spirit. It reminds us that there is no bypassing the Incarnation. The Incarnate Word of God, Christ Jesus, remains the central focus of our salvation and deification. Our creaturely participation in the divine life is always mediated by being in Christ and by being members of his body.
Therefore, the beauty of the doctrine of deification is that it ensures and enhances the full biblical revelation of our call to become sons and daughters formed in the image of Christ, to be temples of the Holy Spirit, and members of the household of God; living and in eternal communion with the Father, through the Son, and in the Holy Spirit.
Catechism of the Catholic Church, 2nd ed. Washington, DC: Twenty-First Printing, 2010.
Irenaeus. The Scandal of the Incarnation: Irenaeus Against the Heresies, Selected and Introduced by Hans Urs von Balthasar. Translated by John Saward. San Francisco: Ignatius Press, 1981.
Keating, Daniel A. Deification and Grace. Naples, FL: Sapientia Press, 2007.
Maximus the Confessor. On the Cosmic Mystery of Jesus Christ. Translated by Paul M. Bowers and Robert Louis Wilken. Crestwood, New York: St. Vladimir’s Seminary Press, 2003.
Nellas, Panayiotis. Deification in Christ; the Nature of the Human Person. Translated by Norman Russell. Crestwood, New York: St. Vladimir’s Seminary Press, 1987.
Thunberg, Lars. The Vision of St. Maximus the Confessor; Man and the Cosmos. Crestwood, New York: St. Vladimir’s Seminary Press, 1985.
Thunberg, Lars. Microcosm and Mediator; the Theological Anthropology of Maximus the Confessor. 2nd ed. Chicago: Open Court Publishing, 1995
 2 Peter 1:4 New American Bible
 Catechism of the Catholic Church, §460
 Ibid., §398
 Irenaeus, The Scandal of the Incarnation: Irenaeus Against the Heresies, Selected and Introduced by Hans Urs von Balthasar, trans. John Saward (San Francisco: Ignatius Press, 1981), 54.
 Ibid., 55
 Daniel A. Keating, Deification and Grace (Naples, FL: Sapientia Press, 2007), 14
 Keating, Deification and Grace, 15,
 Joseph Ratzinger, Dogma and Preaching, trans,. Matthew J. O’Connell (Chicago: Franciscan Herald Press, 1985), 84.
 Irenaeus, Scandals,54
 Ephesians 1:10, “As a plan for the fullness of times, to sum up (recapitulate) all things in Christ, in heaven and on earth.” New American Bible.
 Irenaeus, Scandals, 56
 When the Church Fathers speak of baptism and Eucharist, we must remember that they are summing up what we call today the “sacraments of initiation.” This includes what we in the Western Church call “confirmation.” Today it is traditionally done separate from the baptismal rite, but when baptism is referred to here, we are including both confirmation and baptism, as the Eastern Church does even today.
 Keating, Deification, 43
 Ibid., 44
 Ibid., 45
 Ibid., 95