IntroductionThe concept of theosis (θέωσις) is originally an Eastern Orthodox doctrine, and because it is often misunderstood, it is generally frowned upon by scholars from the western tradition. Within Orthodoxy, the terms “deification,” “divinization” and “theosis” are commonly interchangeable, and mean the same thing. Orthodoxy would argue that this is an early patristic doctrine, clearly enunciated by certain early church fathers like Athanasius, Gregory of Nazianzus, Basil the Great, and Anastasius of Sinai. In fact, Athanasius memorably condensed the entire concept of theosis into an aphorism, “[God] was made man so that we might be made God” (Athanasius, On the Incarnation of the Word, 54.3).
We now turn to the definition of theosis within the Eastern Orthodox tradition. According to Reuschling, “Theōsis is a theological concept denoting the goal of salvation to be union with God made possible through a process of deification, or becoming like God or being made divine.”
Here we encounter the elusive phrase “goal of salvation.” Is this “salvation” justification, or is it “salvation” as in sanctification and subsequently glorification? It seems difficult to tease out a distinction between justification and sanctification with the terse phrase.
We ought to ask ourselves, “Are we united to God at justification, or are we being justified by a process of deification?” Furthermore, how are we united with God? The Western Church has no problem with the concept of Christians being “in Christ” or united with Christ at the new birth. As Paul wrote in the epistle to the Ephesians, “In him we have redemption through his blood, the forgiveness of our trespasses … In him we have obtained an inheritance … In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory” (ESV, Ephesians 1:7–14).Perusing the Westminster Larger Catechism question 69:
Q. 69. What is the communion in grace which the members of the invisible church have with Christ?A. The communion in grace which the members of the invisible church have with Christ, is their partaking of the virtue of his mediation, in their justification, adoption, sanctification, and whatever else, in this life, manifests their union with him. (emphasis mine)
It becomes apparent that the Reformed tradition likewise propounds the concept of “union with Christ,” the details of which goes beyond the scope of this brief discourse. But the notion of theosis is more than that. It means that we are being made more divine, hence the term “divinization.”We must inquire, “Does theosis involve a confounding of ontology between Creator and creature, or some form of absorption into the being of God?” What does Orthodoxy mean when they say that Christians are being deified? The Orthodox Study Bible describes theosis as follows:
“This does not mean we become divine by nature. If we participated in God’s essence, the distinction between God and man would be abolished. What this does mean is that we participate in God’s energy, described by a number of terms in scripture such as glory, love, virtue, and power. We are to become like God by His grace, and truly be His adopted children, but never become like God by nature. … When we are joined to Christ, our humanity is interpenetrated with the energies of God through Christ’s glorified flesh. Nourished by the Blood and Body of Christ, we partake of the grace of God—His strength, His righteousness, His love—and are enabled to serve Him and glorify Him. Thus we, being human, are being deified.”In other words, theosis in Orthodoxy does not mean that man become gods in any ontological sense. Rather, it refers to a process whereby Christians via the participation in God’s “energies,” acquire godly characteristics such as “love, virtue and power,” thereby experiencing communion with God and eventually gaining immortality. These can be identified as what evangelicals describe as sanctification and glorification.
Theosis is a central tenet of Eastern Orthodoxy. This doctrine permeates all of Orthodoxy’s teachings on salvation. This terminology has traditionally been repulsive to the Western Church as it may be misconstrued as the assimilation of man’s essence with God’s essence, thereby confounding foundational doctrines such as divine simplicity and the Creator-creature distinction. This is partially due to the fact that the Western Church has never distinguished God’s essence from His energies.Bartos elucidates, “Yet Eastern theology says very clearly that “becoming god” does not mean an identification with God’s divine nature (essence) but rather something experienced by adoption, by grace, and by imitation. Generally, the theology of the Orthodox Church understands deification as “the religious ideal of Orthodoxy,” and “the central dogma of Orthodoxy.’”
Problems with TheosisWould I therefore be correct to say that the concept of theosis is innocuously palatable for Reformed theology? Not quite.
Contrariwise, there seems to be some apparently insurmountable difficulties between Orthodoxy and Evangelicalism concerning the concept of theosis. Kärkkäinen agrees, “According to the typical textbook wisdom, the main dividing issue between Roman Catholics and Lutherans is the differing interpretation of the doctrine of justification by faith, and the issue between Western and Eastern churches is the irreconcilable breach between understanding salvation in terms of justification and theosis, respectively. Historically, especially Eastern and Western traditions have been considered to be diametrically opposed to each other.”Allow us to look at these differences in some details. The most serious of these is the lack of emphasis on the distinction between justification and sanctification within Orthodoxy’s doctrine of salvation and theosis. As Fairbairn rightly observes that, “Orthodoxy’s emphasis on deification or sanctification to the virtual exclusion of justification creates serious problems for Western evangelicals.”
The paramount evangelical doctrine of forensic justification of the believer by faith alone arguably distinguishes heterodoxy from mainstream evangelicalism. For Evangelicals, justification is already accomplished for the believer, and is not a status that the believer is in a process of acquiring. In A.D. 1672, the Synod of Jerusalem was convened, which issued the Confession of Dositheus directed against Calvinism and her teachings. The confession clearly repudiated the Protestant formulation of sola fide in Article XIII, which states that, “Man is justified, not by faith alone, but also by works.” It becomes evident why Orthodoxy’s doctrinal formulation on salvation deliberately avoids a distinction between justification and sanctification, with a de-emphasis on forensic justification. What the Eastern Orthodox Church needs to cogitate upon is the doctrine of justification.Fairbairn is correct when he states that, “Orthodoxy’s failure to distinguish adequately between justification and sanctification and its lack of emphasis on the former is related to its understanding of grace. We have noticed that Eastern Christendom regards grace as the energies of God which are communicated to people and which deify them.”
Eastern Orthodoxy’s understanding of “grace” is a good example of how theology proper (doctrine of God) affects and permeates all of one’s systematic theology, including soteriology. In Eastern Orthodoxy, there is a distinction between God’s essence and energies. The concept of God’s energies is foreign to the Western Church. Therefore, when Orthodoxy preaches that, in theosis, man becomes more divine, it refers to the infusion of God’s energies into man, and not His essence.So according to Orthodoxy, grace is God’s energy that is continually infused into the believer as a process, which results in man’s eventual divinization. But Protestantism teaches that God’s grace is His unmerited favour in a salvific sense, which is understood as a one-time legal declaration of the sinner as justified. Fairbairn astutely laments that, “The lack of emphasis in Orthodox theology on this aspect of grace contributes to the Eastern failure to stress the nature of salvation as a free gift. This in turn leads to a failure to distinguish between justification as God’s free acceptance of unworthy sinners when we begin to believe, and sanctification as the process of becoming righteous, a process which involves human effort. While the emphasis on the process of deification itself is appropriate, the lack of stress on the event which begins that process results in a significantly distorted view of Christian life.”
Michael Horton highlights an essential dissimilarity between Eastern and Western theology proper, “Crucial to Orthodoxy is the distinction between God’s essence and energies. The West has traditionally acknowledged only uncreated essence (God) and created essence (creatures), so that union with God would mean union with God’s essence. Yet for the East, there is only union with the energies—which are God, but in God’s activity rather than in God’s being. This marks the crucial difference between pagan Greek henōsis (absorption into deity) and theōsis.”In other words, “Western theology operates with two categories: whatever is not created is divine. The Eastern church added a third category: divine energies.” This difference in the understanding of God’s essence and energies led to a cautious rejection of theosis by the Western Church. But the recent resurgence in interest in the Eastern Orthodox doctrine of theosis has led to a re-interpretation of Luther’s understanding of deification. Indeed, the dialogue between Finnish-Lutheran and Russian Orthodoxy has culminated in an influential document on the doctrine of salvation entitled, “Salvation as Justification and Deification.” “The New Interpretation of Luther’s theology, as advanced by the so-called Mannermaa school at the University of Helsinki, has challenged the prevailing German Old School approach,” notes Finnish theologian Kärkkäinen.
But such misinterpretation of Luther’s deification theory is nothing new. The “new interpretation” that justification is deification by the Mannermaa school bears an uncanny resemblance to Osiander’s error. Historically, “Andreas Osiander (1498–1552) thought that he was merely extending Luther’s logic when he argued that, in Christ, the believer participates in the deity of God.”The errors of Osiander have been thoroughly refuted by Philip Melanchthon, Matthias Flacius and John Calvin. According to Calvin, “[Osiander’s] view that Christ is our righteousness solely by his divine nature, whereby he imparts to us “essential righteousness,” was regarded as invalidating the Reformation doctrine of Christ’s sacrifice in the agony of the cross.”
He continues, “That gentleman [Osiander] had conceived something bordering on Manichaeism, in his desire to transfuse the essence of God into men. … He says that we are one with Christ. We agree. But we deny that Christ’s essence is mixed with our own. Then we say that this principle is wrongly applied to these deceptions of his: that Christ is our righteousness because he is God eternal, the source of righteousness, and the very righteousness of God. … Although he [Osiander] may make the excuse that by the term “essential righteousness” he means nothing else but to meet the opinion that we are considered righteous for Christ’s sake, yet he has clearly expressed himself as not content with that righteousness which has been acquired for us by Christ’s obedience and sacrificial death, but pretends that we are substantially righteous in God by the infusion both of his essence and of his quality.”Similar to Eastern Orthodoxy’s teaching on theosis, Osiander alleges “that we are not justified by the grace of the Mediator alone, nor is righteousness simply or completely offered to us in his person, but that we are made partakers in God’s righteousness when God is united to us in essence.”
Hence, the teaching that righteousness is infused denies the Reformation’s clarion call for forensic justification by faith alone, in Christ alone. Similar to Orthodoxy’s salvation by theosis, the imputation of Christ’s righteousness to the believer as a single, particular occurrence is repudiated by Osiander. He asserts “that to be justified is not only to be reconciled to God through free pardon but also to be made righteous, and righteousness is not a free imputation but the holiness and uprightness that the essence of God, dwelling in us, inspires.”Michael Bird justly conclude that, “Calvin’s Christology will not actually allow God’s essential life to be communicated to believers (and rightly so, to avoid the error of Andreas Osiander that we share in God’s essential righteousness in justification).”
He perceives that, “For Calvin, the believer participates only in the human nature of Christ. Moreover, since there can be no interpenetration of the natures in Christ, participation in the human nature of Christ cannot result in a participation in the divine nature. The upshot is that one simply cannot find the ontological purchase needed for a deification theory in Calvin’s Christology. In my mind, Calvin is at best an advocate of a soft form of deification (i.e., participation), but not in the fully orbed Eastern sense.”
ConclusionFor those who understand salvation as a deification process or theosis, the primary message from Protestantism is that Christ has purchased believers with His blood, and through His lifelong obedience in the fulfilment of the Law and His Passion, His perfect righteousness is imputed to believers by faith alone, and in Him alone. Thus, God pronounces believers righteous in Christ, and justified, not via a process of divinization or infusion of grace, but by forensic justification as a legal declaration.
Lastly, it would be prudent for us to give heed to McGowan’s advice that “there are certain key theological affirmations which must be maintained. First, the Creator-creature distinction; second, the ontological difference between God’s being and human being; and third, the doctrine of the two distinct natures of Christ under the one Person of the Logos. The affirmation of these doctrines will distinguish Reformed theology from various forms of deification theology.”
 Wyndy Corbin Reuschling, “The Means and End in 2 Peter 1:3–11: The Theological and Moral Significance of Theōsis,” Journal of Theological Interpretation 8, no. 2 (2014): 276.
 The Orthodox Study Bible: Ancient Christianity Speaks to Today’s World (Nashville: Nelson, 2008), 1691–92.
 Emil Bartos, Deification in Eastern Orthodox Theology (Milton Keynes, UK: Paternoster, 1999), 7.
 Veli-Matti Kärkkäinen, “Deification View,” in Justification: Five Views, ed. Paul Rhodes Eddy, James K. Beilby, and Steven E. Enderlein, Spectrum Multiview Book Series (Downers Grove, IL: IVP Academic, 2011), 219–220.
 Don Fairbairn, “Salvation as Theosis: The Teaching of Eastern Orthodoxy,” Themelios 23, no. 3 (1998): 47.
 Ibid., 49.
 Ibid., 50.
 Michael S. Horton, “Traditional Reformed Response,” in Justification: Five Views, ed. Paul Rhodes Eddy, James K. Beilby, and Steven E. Enderlein, Spectrum Multiview Book Series (Downers Grove, IL: IVP Academic, 2011), 245.
 Michael Horton, Pilgrim Theology: Core Doctrines for Christian Disciples (Grand Rapids, MI: Zondervan, 2012), 328.
 Veli-Matti Kärkkäinen, “Deification View,” 220.
 Michael S. Horton, “Traditional Reformed Response,” 244.
 John Calvin, Institutes of the Christian Religion, ed. John T. McNeill, trans. Ford Lewis Battles, vol. 1, The Library of Christian Classics (Louisville, KY: Westminster John Knox Press, 2011), 3.11.5, 730.
 Ibid., 731.
 John Calvin, Institutes of the Christian Religion, 3.11.6, 731.
 Michael F. Bird, Evangelical Theology: A Biblical and Systematic Introduction (Grand Rapids, MI: Zondervan, 2013), 578.
 Andrew McGowan, “Colossians 3: Deification, Theosis, Participation, or Union with Christ?,” in Theological Commentary: Evangelical Perspectives, ed. R. Michael Allen (London; New York: T&T Clark, 2011), 170.