Theosis, also known as divinization or deification, is a central concept in Eastern Orthodox Christianity that describes the process by which a human being becomes united with God and partakes in the divine nature. It reflects the transformative journey of becoming more like God in holiness and character, ultimately participating in the life of the Trinity. While the term is primarily associated with Eastern Orthodoxy, the underlying idea of becoming one with God can also be found in other Christian traditions, though it may be expressed differently.

Biblical Foundations of Theosis

Old Testament Foreshadowing

The concept of humanity’s union with God is hinted at in the Old Testament, particularly in the creation narrative and the Psalms. These passages reflect the idea that human beings are created in the image of God and are called to share in His divine life.

• Genesis 1:26-27 – “Then God said, ‘Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.’ So God created mankind in his own image, in the image of God he created them; male and female he created them.” (NIV) The creation of humanity in the image of God implies a unique relationship between God and human beings, one that is foundational to the concept of theosis.
• Psalm 82:6 – “I said, ‘You are “gods”; you are all sons of the Most High.'” (NIV) This verse is often interpreted in the context of theosis, suggesting that humans, as children of God, are called to share in His divine nature.

New Testament Fulfillment

The New Testament provides a clearer foundation for the doctrine of theosis, particularly through the writings of the Apostle Paul and the teachings of Jesus. The idea that believers are united with Christ and participate in the divine nature is central to the New Testament’s message of salvation and transformation.

• 2 Peter 1:4 – “Through these he has given us his very great and precious promises, so that through them you may participate in the divine nature, having escaped the corruption in the world caused by evil desires.” (NIV) This verse is often cited as a key biblical basis for theosis, directly stating that believers are called to participate in the divine nature.
• John 17:21-23 – “That all of them may be one, Father, just as you are in me and I am in you. May they also be in us so that the world may believe that you have sent me. I have given them the glory that you gave me, that they may be one as we are one—I in them and you in me—so that they may be brought to complete unity. Then the world will know that you sent me and have loved them even as you have loved me.” (NIV) In this prayer, Jesus expresses the desire for His followers to be united with Him and the Father, reflecting the ultimate goal of theosis: unity with God.
• Galatians 2:20 – “I have been crucified with Christ and I no longer live, but Christ lives in me. The life I now live in the body, I live by faith in the Son of God, who loved me and gave himself for me.” (NIV) Paul’s identification with Christ and the indwelling of Christ within the believer is a key aspect of theosis, emphasizing the transformative union between the believer and God.
• 1 John 3:2 – “Dear friends, now we are children of God, and what we will be has not yet been made known. But we know that when Christ appears, we shall be like him, for we shall see him as he is.” (NIV) This verse speaks to the future transformation and glorification of believers, aligning with the idea of becoming more like God in the process of theosis.

Theological Significance of Theosis

The Nature of Salvation

In Orthodox theology, theosis is not just a process of moral improvement or sanctification but is understood as the very essence of salvation. Salvation is seen as a dynamic process of transformation in which believers are gradually conformed to the image of Christ and brought into full communion with the Trinity.

1. Union with God: Theosis emphasizes the ultimate goal of Christian life as union with God. This union is not merely an external relationship but a deep participation in the life and energy of the Triune God. It is the fulfillment of humanity’s original purpose, as intended by God at creation.
   

   Biblical Reference: John 15:4-5, “Remain in me, as I also remain in you. No branch can bear fruit by itself; it must remain in the vine. Neither can you bear fruit unless you remain in me. I am the vine; you are the branches. If you remain in me and I in you, you will bear much fruit; apart from me you can do nothing.” (NIV) This passage emphasizes the intimate union between Christ and believers, which is foundational to theosis.

2. Participation in the Divine Life: Theosis is often described as participation in the divine life, a concept that is rooted in the early Church Fathers, particularly in the writings of St. Athanasius, who famously said, “God became man so that man might become god” (On the Incarnation, 54). This participation is not a literal becoming of God in essence but rather a sharing in God’s divine energies, which are His actions and presence in the world.
   

   Biblical Reference: Ephesians 3:16-19, “I pray that out of his glorious riches he may strengthen you with power through his Spirit in your inner being, so that Christ may dwell in your hearts through faith. And I pray that you, being rooted and established in love, may have power, together with all the Lord’s holy people, to grasp how wide and long and high and deep is the love of Christ, and to know this love that surpasses knowledge—that you may be filled to the measure of all the fullness of God.” (NIV) This passage speaks to the experience of being filled with the fullness of God, which aligns with the concept of theosis.

3. Transformation and Sanctification: Theosis involves a process of sanctification, where believers are transformed into the likeness of Christ through the work of the Holy Spirit. This transformation is both a present reality and a future hope, as believers are gradually conformed to the image of God and will one day be fully glorified in Him.
   

   Biblical Reference: 2 Corinthians 3:18, “And we all, who with unveiled faces contemplate the Lord’s glory, are being transformed into his image with ever-increasing glory, which comes from the Lord, who is the Spirit.” (NIV) Paul speaks of the ongoing transformation of believers into the image of Christ, which is central to the process of theosis.

The Role of the Incarnation

The incarnation of Jesus Christ is central to the doctrine of theosis. In Orthodox theology, the incarnation is not only about God becoming man to save humanity from sin but also about enabling humanity to become united with God. Christ, as the God-man, bridges the gap between the divine and human natures, making theosis possible.

1. Christ as the Perfect Image of God: Jesus Christ is the perfect image of God, fully embodying both divinity and humanity. Through His incarnation, life, death, and resurrection, He restores the image of God in humanity and opens the way for believers to participate in the divine nature.
   

   Biblical Reference: Colossians 1:15-20, “The Son is the image of the invisible God, the firstborn over all creation. For in him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things have been created through him and for him. He is before all things, and in him all things hold together. And he is the head of the body, the church; he is the beginning and the firstborn from among the dead, so that in everything he might have the supremacy. For God was pleased to have all his fullness dwell in him, and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross.” (NIV) This passage highlights Christ’s role as the image of God and the reconciler of all things, central themes in theosis.

2. The Hypostatic Union: The doctrine of the hypostatic union, which affirms that Christ is fully God and fully man in one person, is foundational to theosis. By uniting human nature with the divine in Himself, Christ makes it possible for human beings to share in the divine life.
   

   Biblical Reference: John 1:14, “The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who came from the Father, full of grace and truth.” (NIV) The incarnation of the Word is the basis for the possibility of theosis, as it brings the divine and human natures together.

The Role of the Holy Spirit

Theosis is a Trinitarian process, involving the work of the Father, the Son, and the Holy Spirit. The Holy Spirit plays a crucial role in the process of theosis, as it is through the Spirit that believers are transformed, sanctified, and brought into communion with God.

1. The Indwelling of the Holy Spirit: The Holy Spirit dwells within believers, guiding them in the path of holiness and enabling them to participate in the divine nature. The Spirit’s work in the believer’s life is essential for the process of theosis.
   

   Biblical Reference: Romans 8:11, “And if the Spirit of him who raised Jesus from the dead is living in you, he who raised Christ from the dead will also give life to your mortal bodies because of his Spirit who lives in you.” (NIV) The indwelling of the Holy Spirit is the source of life and transformation, central to theosis.

2. The Fruit of the Spirit: The transformation that takes place through theosis is evidenced by the fruit of the Spirit, which are the characteristics of the divine nature being manifest in the life of the believer.
   

   Biblical Reference: Galatians 5:22-23, “But the fruit of the Spirit is love, joy, peace, forbearance, kindness, goodness, faithfulness, gentleness and self-control. Against such things there is no law.” (NIV) The fruit of the Spirit reflects the character of God, which believers are called to embody through theosis.

Theological Debates and Clarifications

Distinction Between Essence and Energies

One of the key theological distinctions in Orthodox theology related to theosis is the distinction between God’s essence and His energies. This distinction helps to clarify how human beings can participate in the divine nature without compromising the transcendence and incomprehensibility of God.

1. Essence-Energies Distinction: According to Orthodox theology, God’s essence is His inner, incomprehensible nature, which remains beyond the reach of human knowledge and participation. However, God’s energies are His actions and presence in the world, through which He communicates with and interacts with creation. Theosis involves participation in God’s energies, not His essence.
   

   Theological Reference: This distinction was most notably articulated by St. Gregory Palamas in the 14th century, in response to debates with the Barlaamites. Palamas argued that theosis is possible because of the uncreated energies of God, which are fully God but distinct from His essence.

2. Avoiding Pantheism: The essence-energies distinction is important for avoiding pantheism, the idea that creation is identical with God. By participating in God’s energies, believers are united with God while still maintaining their distinctiveness as creatures.
   

   Biblical Reference: 2 Peter 1:4, “Through these he has given us his very great and precious promises, so that through them you may participate in the divine nature, having escaped the corruption in the world caused by evil desires.” (NIV) Participation in the divine nature is understood as participation in God’s energies, not His essence.

The Role of Grace and Human Cooperation

Theosis emphasizes the importance of both divine grace and human cooperation in the process of salvation. While theosis is ultimately a work of God’s grace, it also requires the active participation of the believer.

1. Synergy: Orthodox theology often speaks of synergy in the context of theosis, meaning that there is a cooperative relationship between divine grace and human effort. Salvation is not earned by human works, but neither is it accomplished without the believer’s active participation in the life of God.
   

   Biblical Reference: Philippians 2:12-13, “Therefore, my dear friends, as you have always obeyed—not only in my presence, but now much more in my absence—continue to work out your salvation with fear and trembling, for it is God who works in you to will and to act in order to fulfill his good purpose.” (NIV) This passage highlights the cooperative nature of salvation, where believers are called to work out their salvation, while recognizing that it is God who is at work within them.

2. The Role of the Sacraments: In Orthodox theology, the sacraments are understood as means of grace that facilitate the process of theosis. Through the sacraments, particularly baptism, chrismation, and the Eucharist, believers receive the grace of God and are incorporated more fully into the divine life.
   

   Biblical Reference: John 6:56, “Whoever eats my flesh and drinks my blood remains in me, and I in them.” (NIV) The Eucharist is seen as a key means by which believers are united with Christ and participate in His divine life.

The Ultimate Goal of Theosis

The ultimate goal of theosis is the complete transformation and glorification of the believer, which will be fully realized in the eschaton (the end times). This future hope is rooted in the promise of resurrection and the believer’s participation in the glory of God.

1. The Beatific Vision: In the eschatological context, theosis culminates in the beatific vision, where believers will see God face to face and be fully united with Him. This vision is the ultimate fulfillment of the believer’s longing for communion with God.
   

   Biblical Reference: 1 Corinthians 13:12, “For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known.” (NIV) This verse speaks to the future fulfillment of theosis, where believers will know God fully and be fully known by Him.

2. Resurrection and Glorification: Theosis is closely tied to the doctrine of the resurrection, where believers will be raised with glorified bodies and will share in the glory of Christ. This glorification is the final stage of theosis, where the believer’s transformation into the likeness of God is complete.
   

   Biblical Reference: Philippians 3:20-21, “But our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ, who, by the power that enables him to bring everything under his control, will transform our lowly bodies so that they will be like his glorious body.” (NIV) The promise of resurrection and transformation into the likeness of Christ is the ultimate goal of theosis.

Practical Implications for Worship and Devotion

The Practice of Prayer and Contemplation

Prayer and contemplation are central to the process of theosis. Through prayer, believers enter into communion with God, opening themselves to the transformative work of the Holy Spirit.

1. The Jesus Prayer: In Orthodox spirituality, the Jesus Prayer (“Lord Jesus Christ, Son of God, have mercy on me, a sinner”) is a central practice that helps believers cultivate a continual awareness of God’s presence and their need for His mercy. This prayer is seen as a means of drawing closer to God and participating in His divine life.
   

   Biblical Reference: 1 Thessalonians 5:17, “Pray without ceasing.” (NIV) The call to constant prayer is integral to the process of theosis, as it fosters ongoing communion with God.

2. Hesychasm: Hesychasm is a form of contemplative prayer that seeks inner stillness and direct experience of God’s presence. Practiced by many Orthodox monks, hesychasm is seen as a path to theosis, where the believer encounters the uncreated light of God and is transformed by it.
   

   Biblical Reference: Matthew 6:6, “But when you pray, go into your room, close the door and pray to your Father, who is unseen. Then your Father, who sees what is done in secret, will reward you.” (NIV) The emphasis on private, contemplative prayer aligns with the practice of hesychasm in the pursuit of theosis.

The Role of the Sacraments

The sacraments are seen as essential means of grace that facilitate the process of theosis. Through the sacraments, believers are united with Christ, receive the Holy Spirit, and are drawn deeper into the life of the Trinity.

1. Baptism: In Orthodox theology, baptism is the beginning of theosis. Through baptism, the believer is united with Christ in His death and resurrection, cleansed from sin, and initiated into the divine life.
   

   Biblical Reference: Romans 6:3-4, “Or don’t you know that all of us who were baptized into Christ Jesus were baptized into his death? We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life.” (NIV) Baptism is the sacrament that initiates believers into the new life of theosis.

2. Eucharist: The Eucharist is central to the ongoing process of theosis, as it is through receiving the body and blood of Christ that believers are nourished spiritually and drawn deeper into union with God.
   

   Biblical Reference: John 6:56, “Whoever eats my flesh and drinks my blood remains in me, and I in them.” (NIV) The Eucharist is the sacrament of communion with Christ, essential to the process of theosis.

The Pursuit of Holiness and Virtue

Theosis involves the cultivation of holiness and virtue, as believers seek to conform their lives to the image of Christ. This involves both the avoidance of sin and the active pursuit of the virtues that reflect the character of God.

1. The Virtues: In Orthodox spirituality, the virtues are seen as expressions of the divine nature, and cultivating them is essential to the process of theosis. These virtues include humility, love, patience, and self-control, among others.
   

   Biblical Reference: 2 Peter 1:5-7, “For this very reason, make every effort to add to your faith goodness; and to goodness, knowledge; and to knowledge, self-control; and to self-control, perseverance; and to perseverance, godliness; and to godliness, mutual affection; and to mutual affection, love.” (NIV) The pursuit of these virtues is integral to the process of becoming more like God.

2. Repentance and Confession: Repentance and confession are also central to the process of theosis, as they involve turning away from sin and realigning oneself with God’s will. Through repentance, believers are continually purified and brought closer to God.
   

   Biblical Reference: 1 John 1:9, “If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.” (NIV) The practice of confession and repentance is essential for the ongoing process of theosis.

Broader Biblical Themes

The Image of God

The concept of theosis is closely connected to the biblical theme of the image of God. Humanity was created in the image of God, and theosis is understood as the process of restoring and perfecting that image through union with Christ.

• Genesis 1:26-27 – “Then God said, ‘Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.’ So God created mankind in his own image, in the image of God he created them; male and female he created them.” (NIV) The creation of humanity in God’s image lays the foundation for theosis, as believers are called to grow into that image through union with Christ.

The Kingdom of God

Theosis is also related to the biblical theme of the Kingdom of God. As believers are transformed and united with God, they participate in the life of the Kingdom, both in the present and in its future fulfillment.

• Matthew 6:33 – “But seek first his kingdom and his righteousness, and all these things will be given to you as well.” (NIV) The pursuit of the Kingdom of God is part of the process of theosis, as believers align their lives with God’s will and participate in His divine life.

The Resurrection and Eternal Life

Theosis is ultimately fulfilled in the resurrection and the promise of eternal life. In the resurrection, believers will be fully united with God and will share in His glory forever.

• 1 Corinthians 15:49 – “And just as we have borne the image of the earthly man, so shall we bear the image of the heavenly man.” (NIV) The resurrection is the culmination of theosis, where believers are fully conformed to the image of Christ and share in His eternal life.

Legacy and Influence in Christian Doctrine and Church History

Influence on Eastern Orthodox Theology

Theosis is a central concept in Eastern Orthodox theology and spirituality, deeply influencing the Church’s understanding of salvation, the sacraments, and the Christian life.

1. Patristic Foundations: The doctrine of theosis is rooted in the writings of the Church Fathers, particularly those of the Eastern tradition, such as St. Athanasius, St. Gregory of Nyssa, and St. Maximus the Confessor. These theologians emphasized the transformative and participatory nature of salvation, which is realized through union with God.
   

   Theological Reference: St. Athanasius’s statement, “God became man so that man might become god,” encapsulates the Orthodox understanding of theosis as the ultimate goal of the Christian life.

2. Liturgical and Sacramental Life: Theosis is reflected in the liturgical and sacramental life of the Orthodox Church, where the faithful are continually drawn into the divine life through the celebration of the Eucharist, the practice of prayer, and the cultivation of virtue.
   

   Liturgical Reference: The Divine Liturgy, particularly the anaphora, often includes prayers that reflect the theme of theosis, asking God to transform the faithful and bring them into union with Him.

Influence on Western Christianity

While the term “theosis” is more commonly associated with Eastern Orthodoxy, the underlying concept of becoming more like God and participating in His divine life has also been influential in Western Christianity, particularly in mystical and ascetical traditions.

1. Mystical Theology: Western mystical theologians, such as St. John of the Cross and St. Teresa of Avila, have explored themes similar to theosis, focusing on the believer’s union with God through contemplation and the transformative power of divine grace.
   

   Theological Reference: St. John of the Cross’s concept of the “dark night of the soul” reflects the process of purification and union with God, which parallels the Orthodox understanding of theosis.

2. Protestant Perspectives: While the term “theosis” is less commonly used in Protestant theology, the concept of sanctification and the believer’s growth in holiness reflects similar ideas. The Reformed tradition, in particular, emphasizes the transformative work of the Holy Spirit in conforming believers to the image of Christ.
   

   Theological Reference: John Calvin’s emphasis on union with Christ as the foundation of sanctification and the Christian life reflects a Reformed parallel to the concept of theosis.

Conclusion

Theosis is a profound and central concept in Christian theology, particularly within the Eastern Orthodox tradition, that describes the process of becoming united with God and partaking in the divine nature. Rooted in Scripture and developed by the Church Fathers, theosis emphasizes the transformative journey of salvation, where believers are gradually conformed to the image of Christ and brought into full communion with the Trinity.

From a Christian worldview, theosis represents the ultimate goal of the Christian life: union with God and participation in His divine life. This process involves the work of the Holy Spirit, the practice of prayer and the sacraments, and the cultivation of virtue and holiness. Theosis is not merely about moral improvement but about being transformed into the likeness of God, sharing in His divine nature, and experiencing the fullness of life in Christ.

The doctrine of theosis has had a profound influence on Christian theology, spirituality, and worship, particularly in the Eastern Orthodox Church. It offers a vision of salvation that is both deeply personal and profoundly communal, inviting believers to participate in the life of God and to be transformed by His grace. As Christians continue to seek a deeper relationship with God, the doctrine of theosis provides a powerful framework for understanding the transformative and participatory nature of the Christian life.