Need some help with understanding "theosis"

A measure of the frequency of this topic: a search on "theosis, divinization, "via unitiva"" in my library brings up 1, 244 articles in 453 resources.

Okay, let's start by dispelling the belief that this is an Orthodox thing:

Edward Faulk said:

50. What is theosis?

Both the Latin Church and the Eastern Catholic Churches feature this idea as a central point in their theology. What is called “theosis” in the East is called “divinization” in the West. It is the process of becoming more like God. Many of the church fathers speak this simple truth, which is commonly attributed to Saint Athanasius (and to other church fathers such as Saint Augustine): “God became man that man might become God.” Note that we do not become “a god” but, rather, are incorporated into the One God.
This is, as Saint Peter tells us, “partake[ing] of the divine nature.” Theosis is that process by which we strip away all that is not of God. We do not give up our selves, for that is a precious gift from God. We are, however, to find the true self in service to God and his people and, thereby, to grow in knowledge and love of God.
The Greek word metanoia is frequently associated with theosis. The word means “a conversion, a change of heart.” Saint Paul speaks of conversion as a turning away from something and a turning toward something else. This is precisely the concept of metanoia, and it is the idea behind theosis. We turn from the things of this world—especially from sin—and turn toward God. By participating in the mysteries (sacraments) we are nourished and helped along this path so that, when we finally “fall asleep in the Lord” (in general, Eastern Catholics don’t say “die” because we don’t cease to exist, which is what that term implies), we are so much like God that we are welcomed into his presence.


Edward Faulk, 101 Questions and Answers on Eastern Catholic Churches (New York; Mahwah, NJ: Paulist Press, 2007), 63.

You will also see the term "via unitiva" used as an overlapping concept

It is also not completely foreign to Lutheran thought see Mannermaa, T. “Justification and Theosis in Lutheran-Orthodox Perspective” In Union with Christ: The New Finnish Interpretation of Luther, edited by C. E. Braaten and R. W. Jenson, 25–41. Grand Rapids: Eerdmans, 1998.

For the Anglicans I draw from Wikipedia:

Wikipedia: Divinization said:

Out of the English Reformation, an understanding of salvation in terms closely comparable to the Orthodox doctrine of theosis was recognized in the Anglican tradition, J. Bloor examines deification/theosis in the late Anglican Priest and theologian Canon A. M. (Donald) Allchin, but it is also explored in the writings of Lancelot Andrewes, who described salvation in terms vividly reminiscent of the early fathers:

show previous quotes

Lancelot Andrewes said:

Whereby, as before He of ours, so now we of His are made partakers. He clothed with our flesh, and we invested with His Spirit. The great promise of the Old Testament accomplished, that He should partake our human nature; and the great and precious promise of the New, that we should be “consortes divinae naturae”, “partake his divine nature,” both are this day accomplished.

The following quote is the standard formulation of the concept - although this is not the most common translation:

Athanasius said:

“God became humanized so that humans might become divinized.”

Bradley Nassif, Bringing Jesus to the Desert: Uncover the Ancient Culture, Discover Hidden Meanings, ed. Gary M. Burge, Ancient Context, Ancient Faith (Grand Rapids, MI: Zondervan, 2011), 49.

As shown by the Wikipedia article of divinization (which has less of an Eastern bias than the article on theosis (Eastern Orthodox theology), the idea is firmly entrenched in Patristics and Scripture:

Wikipedia: divinization said:

Patristic writings

There were many varied references to divinization in the writings of the Church Fathers.

In the second century, Irenaeus, bishop of Lyons (c. 130–202) said that God "became what we are in order to make us what he is himself." Irenaeus also wrote, "If the Word became a man, It was so men may become gods." He added: "Do we cast blame on him [God] because we were not made gods from the beginning, but were at first created merely as men, and then later as gods? Although God has adopted this course out of his pure benevolence, that no one may charge him with discrimination or stinginess, he declares, "I have said, Ye are gods; and all of you are sons of the Most High." ... For it was necessary at first that nature be exhibited, then after that what was mortal would be conquered and swallowed up in immortality."

At about the same time, Clement of Alexandria (c. 150–215), wrote: "Yea, I say, the Word of God became a man so that you might learn from a man how to become a god." Clement further stated that "if one knows himself, he will know God, and knowing God will become like God. . . . His is beauty, true beauty, for it is God, and that man becomes a god, since God wills it. So Heraclitus was right when he said, 'Men are gods, and gods are men.'" Clement of Alexandria also stated that "he who obeys the Lord and follows the prophecy given through him ... becomes a god while still moving about in the flesh."

Justin Martyr c. 100–165) insisted that in the beginning men "were made like God, free from suffering and death," and that they are thus "deemed worthy of becoming gods and of having power to become sons of the highest."

Athanasius, bishop of Alexandria (c. 296–373), stated his belief in literal deification:"The Word was made flesh in order that we might be made gods. ... Just as the Lord, putting on the body, became a man, so also we men are both deified through his flesh, and henceforth inherit everlasting life." Athanasius also observed: "For the Son of God became man so that we might become God."

Augustine of Hippo (354–430) said: "But he himself that justifies also deifies, for by justifying he makes sons of God. 'For he has given them power to become the sons of God' [referring to John 1:12]. If then we have been made sons of god, we have also been made gods." "To make human beings gods," Augustine said, "He was made man who was God" (sermon 192.1.1). Augustine goes on to write that "[they] are not born of His Substance, that they should be the same as He, but that by favour they should come to Him... (Ibid)".

Other references to divinization in the writings of the Church Fathers include the following:

• Irenaeus (c. 130-200)
  • "[T]he Word of God, our Lord Jesus Christ, who did, through His transcendent love, become what we are, that He might bring us to be even what He is Himself."
  • "'For we cast blame upon [God], because we have not been made gods from the beginning, but at first merely men, then at length gods; although God has adopted this course out of His pure benevolence, that no one may impute to Him invidiousness or grudgingness he declares, "I have said, Ye are gods; and all of you are sons of the Most High." "
  • "For it was necessary, at first, that nature should be exhibited; then, after that, that what was mortal should be conquered and swallowed up by immortality, and the corruptible by incorruptibility, and that man should be made after the image and likeness of God."
• Clement of Alexandria (c. 150-215)
  • "The Word of God became man, that thou mayest learn from man how man may become God."
  • "For if one knows himself, he will know God; and knowing God, he will be made like God"
  • "His is beauty, the true beauty, for it is God; and that man becomes God, since God so wills. Heraclitus, then, rightly said, “Men are gods, and gods are men.” For the Word Himself is the manifest mystery: God in man, and man God"
  • "He who listens to the Lord, and follows the prophecy given by Him, will be formed perfectly in the likeness of the teacher—made a god going about in flesh."
  • "And to be incorruptible is to participate in divinity..."
• Justin Martyr (c. 100-165)
  • "[Men] were made like God, free from suffering and death, provided that they kept His commandments, and were deemed deserving of the name of His sons, and yet they, becoming like Adam and Eve, work out death for themselves; let the interpretation of the Psalm be held just as you wish, yet thereby it is demonstrated that all men are deemed worthy of becoming “gods,” and of having power to become sons of the Highest."
• Theophilus of Antioch (c. 120-190)
  • "For if He had made him immortal from the beginning, He would have made him God. Again, if He had made him mortal, God would seem to be the cause of his death. Neither, then, immortal nor yet mortal did He make him, but, as we have said above, capable of both; so that if he should incline to the things of immortality, keeping the commandment of God, he should receive as reward from Him immortality, and should become God..."
• Hippolytus of Rome (c. 170-235)
  • "And you shall be a companion of the Deity, and a co-heir with Christ, no longer enslaved by lusts or passions, and never again wasted by disease. For you have become God: for whatever sufferings you underwent while being a man, these He gave to you, because you were of mortal mould, but whatever it is consistent with God to impart, these God has promised to bestow upon you, because you have been deified, and begotten unto immortality."
  • "If, therefore, man has become immortal, he will also be God. And if he is made God by water and the Holy Spirit after the regeneration of the laver he is found to be also joint-heir with Christ after the resurrection from the dead."
• Athanasius of Alexandria (c. 296-373)
  • "Therefore He was not man, and then became God, but He was God, and then became man, and that to deify us"
  • "for as the Lord, putting on the body, became man, so we men are deified by the Word as being taken to Him through His flesh."
  • "For He was made man that we might be made God."
• Gregory of Nyssa (c. 335-395)
  • "Since the God who was manifested infused Himself into perishable humanity for this purpose, viz. that by this communion with Deity mankind might at the same time be deified, for this end it is that, by dispensation of His grace, He disseminated Himself in every believer."
  • "For just as He in Himself assimilated His own human nature to the power of the Godhead, being a part of the common nature, but not being subject to the inclination to sin which is in that nature (for it says: "He did no sin, nor was deceit found in his mouth), so, also, will He lead each person to union with the Godhead if they do nothing unworthy of union with the Divine."
• Augustine of Hippo (c. 354-430)
  • "'For He hath given them power to become the sons of God.'^{[John 1:12]} If we have been made sons of God, we have also been made gods."
• Maximus the Confessor
  • "Nothing in theosis is the product of human nature, for nature cannot comprehend God. It is only the mercy of God that has the capacity to endow theosis unto the existing... In theosis, man (the image of God) becomes likened to God, he rejoices in all the plenitude that does not belong to him by nature, because the grace of the Spirit triumphs within him, and because God acts in him."
• Cyril of Alexandria
  • "For we too are sons and gods by grace, and we have surely been brought to this wonderful and supernatural dignity since we have the Only Begotten Word of God dwelling within us."
• Gregory of Nazianzus
  • implores humankind to "become gods for (God's) sake, since (God) became man for our sake.".
  • Likewise, he argues that the mediator "pleads even now as Man for my salvation; for He continues to wear the Body which He assumed, until He make me God by the power of His Incarnation."
  • "Through the medium of the mind he had dealings with the flesh, being made that God on earth, which is Man: Man and God blended. They became a single whole, the stronger side predominating, in order that I might be made God to the same extent that he was made man."
• Basil of Caesarea stated that "becoming a god is the highest goal of all"

Biblical citations

• Paul the Apostle taught in numerous passages that men are sons of God (as in chapter 8 of Paul's Epistle to the Romans). Paul conceives of the resurrection as immortalization of both the body and the soul (1 Cor 15:42-49). 2 Corinthians 3:17-18 says that "we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another."
• In John 10:34, Jesus defends himself against a charge of blasphemy by stating: "Have I not said that ye are gods?" It is widely believed that Jesus is referring to Psalms 82:6 in saying "Ye are gods and children of the most high."
• Christ's defence against the charge of blasphemy includes the following passages from John 10:33–36

The Jews answered him, saying, For a good work we stone thee not; but for blasphemy; and because that thou, being a man, makest thyself God. Jesus answered them, Is it not written in your law, I said, Ye are gods? If he called them gods, unto whom the word of God came, and the scripture cannot be broken; Say ye of him, whom the Father hath sanctified, and sent into the world, Thou blasphemest; because I said, I am the Son of God?

• In (1 John 5:4—5;Revelation 2:7-11), the apostle, John the Beloved, speaks about how men can overcome the world, as Christ did, through Christ's sacrifice.
• There are several Bible verses which, if summarized state that, through Christ, men may become "heirs of God and joint heirs with Christ" and "will inherit all things" just as Christ inherits all things.

Unfortunately, my first choices for reading are not yet available in Logos. But I would suggest starting with non-technical works then move to the Desert Fathers. These are available in Logos:

• Nassif, Bradley. Bringing Jesus to the Desert: Uncover the Ancient Culture, Discover Hidden Meanings. Edited by Gary M. Burge. Ancient Context, Ancient Faith. Grand Rapids, MI: Zondervan, 2011.
• Webber, Meletios. Bread & Water, Wine & Oil: An Orthodox Christian Experience of God. Ben Lomond, CA: Conciliar Press, 2007.
• McLaren, Brian D. Finding Our Way Again: The Return of the Ancient practices—The Ancient Practices Series. Nashville: Thomas Nelson, 2008.
• Boosalis, Harry. Knowledge of God: Ancient Spirituality of the Christian East. South Canaan, PA: St. Tikhon’s Seminary Press, 2009.
• Bernstein, A. James. Surprised by Christ: My Journey from Judaism to Orthodox Christianity. Chesterton, IN: Ancient Faith Publishing, 2008.
• Papavassiliou, Vassilios. Thirty Steps to Heaven: The Ladder of Divine Ascent for All Walks of Life. Chesterton, IN: Ancient Faith Publishing, 2013.

Some full-fledged studies:

• Nellas, Panayiotis. Deification in Christ: Orthodox Perspectives on the Nature of the Human Person. Edited by Costa Carras with Christos Yannaras, Kallistos of Diokleia. Translated by Norman Russell. 5th ed. Contemporary Greek Theologians. Crestwood, NY: St Vladimir’s Seminary Press, 1987.
• Mantzaridis, Georgios I. The Deification of Man: St Gregory Palamas and the Orthodox Tradition. Edited by Christos Yannaras and Costa Carras. Translated by Liadain Sherrard. Vol. Two. Contemporary Greek Theologians. Crestwood, NY: St. Vladimir’s Seminary Press, 1984.
• Clendenin, Daniel B. Eastern Orthodox Theology: A Contemporary Reader. 2nd ed. Grand Rapids, MI: Baker Academic, 2003.
• Harrison, Nonna Verna. God’s Many-Splendored Image: Theological Anthropology for Christian Formation. Grand Rapids, MI: Baker, 2010. (Avoids the term theosis because of potential misunderstanding.)
• Stevenson, Kenneth. Liturgy and Interpretation. SCM Studies in Worship and Liturgy. London: SCM Press, 2011. (Less directly but crosses multiple traditions including Anglican).
• Hanson, K. C., Stephen Finlan, and Vladimir Kharlamov, eds. Theōsis: Deification in Christian Theology. Vol. 52. Princeton Theological Monograph Series. Eugene, OR: Pickwick Publications, 2006.

That should get you far enough to see that there is a relationship to sanctification but theosis means considerably more. You should be ready to handle the primary sources after reading a couple from each list.

Steve provides an excellent list.