The Undivided Light: The Holy Trinity (Part 6 of 7)

The Trinity and Theosis, Participation in the Undivided Life

Summary Introduction
This is the sixth post in The Undivided Light, a Wednesday summer study series on the Holy Trinity in Oriental Orthodox tradition. The first five posts worked through who God is: the revelation of Pentecost, the Father as Source Without Origin, the eternal Son begotten not made, the Holy Spirit as the living breath, and the Syriac vocabulary of kyano, qnoma, and parsopa. This post asks the question those five were building toward: what does any of it mean for us? The answer the tradition gives is theosis, participation in the very life of God, accomplished by the Father’s will, through the Son’s Incarnation, and by the indwelling of the Holy Spirit. Four fathers guide the reading: Athanasius of Alexandria, Cyril of Alexandria, Ephrem the Syrian, and Severus of Antioch. The post closes where the theology has always been pointing: the altar of the Holy Qurbana, where the exchange Ephrem described in seven words, “He gave us divinity, we gave him humanity”, is enacted week after week in the life of the Malankara faithful.
Fair warning to the reader, this is a long post and a bit technical. Kindly take your time to read carefully and understand the teaching of the Church.

This blog is called Seeking Theosis, and yet in six years of writing I have rarely stopped to sit with the word itself for a full post. This week, in the sixth instalment of our summer study, that is exactly what we are going to do. Because if the first five weeks of this series have been about who God is, this week is about why any of it matters for you and me. And the tradition’s answer to that question is contained in this single Greek word: theosis.

Theosis is usually translated as deification or divinization, and both translations immediately raise an eyebrow, as they should. Does the Church really teach that human beings become God? The short answer is no, and also yes, and the space between that no and that yes is where the whole Gospel lives.

But before the definitions, a scene. Think of the moment in the Holy Qurbana just after we have received the Mysteries. We return to our place. The choir is singing. And for a moment, if the heart is attentive, there is a stillness in which an astonishing thing has just occurred and almost nobody speaks of it in these terms: the eternal God has given Himself to be our food. Not a symbol of Himself. Not a reminder of Himself. Himself. The tradition insists that something happens to us in that moment. We are not merely forgiven. We are being changed, slowly, communion by communion, prayer by prayer, into a creature that shares in the very life of God. That change is theosis.

There is a sentence that stops most people the first time they read it. It stopped me the first time I read it, and it has not quite let me go since. It comes from St. Athanasius of Alexandria, the same fourth-century archbishop whose defence of the Nicene faith we looked at in the third post of this series, and it is perhaps the most concentrated summary of the entire Gospel ever written in a single line.

“He became human so that we might become divine.”

Not that we might be forgiven, though forgiveness is part of it. Not that we might be guided or improved or inspired, though all of those things are also true. But that the infinite distance between the Creator and the creature might be crossed not just from God’s side toward us but from our side toward God, so that the human person arrives, by grace, at a genuine participation in the life that God lives by nature.

This is theosis. And it cannot be separated from the Trinity. Theosis is not a vague spiritual aspiration toward a generic divine experience. It is a precisely Trinitarian event: the human person drawn by the Spirit into union with the Son, and through the Son brought into the life of the Father. Every dimension of theosis has a Trinitarian shape, and understanding that shape is what this post is about.

Four fathers guide us here: Athanasius of Alexandria, who gave us the foundational statement of theosis and its Trinitarian logic; Cyril of Alexandria, whose theology of participation through the Son in the Spirit is the most developed account of theosis in the Oriental Orthodox tradition; Ephrem the Syrian, who expressed the mystery of theosis in Syriac verse of extraordinary beauty and doctrinal precision; and Severus of Antioch, who connected the theology of theosis to the lived sacramental life of the Church and particularly to the epiclesis of the Qurbana. Together, these four voices give us what is perhaps the most important theological claim this series has made: that the Trinity is not a doctrine we study from the outside. It is a life we are invited to enter from within.

What Theosis Is and What It Is Not

Before we come to the fathers, it is worth being clear about what the tradition means by theosis, because the word is sometimes misunderstood in ways that make it sound either more exotic than it is or more dangerous than it is.

Theosis is sometimes translated as deification or divinisation, and these translations, while accurate, can give the wrong impression. They can make it sound as if the human person is being turned into God in some way that erases the distinction between Creator and creature, as if the goal of the Christian life is for the human person to dissolve into the divine and lose their own identity in the process.

Theosis does not mean that human beings become God by nature. We do not acquire the divine essence. We do not become a fourth person of the Trinity. We do not stop being creatures. The distinction between the Creator and the creature is never erased, not in this life and not in the age to come. Any teaching that blurs that line has left the Orthodox faith behind.

What the Fathers taught instead rests on a distinction we have been circling all series: the difference between what God is by nature and what we may receive by grace. The Son is God by nature, begotten of the Father before all ages, as we saw in the third post. We become sons and daughters by grace, by adoption, by gift. The Son is divine the way fire is hot. We become divine the way iron in the fire becomes hot: truly, really, glowing with a heat that is not its own, while remaining iron all the way through.

The patristic tradition is clear that this is not what theosis means. The distinction between God and the creature is never abolished. The human person does not become God by nature. What happens in theosis is that the human person, remaining fully and genuinely human, is given a real and genuine participation in the divine life, not by becoming what God is by nature but by receiving, through grace, what God freely gives from His own life. The creature remains a creature. But the creature is filled with the life of the Creator in a way that transforms it from within, drawing it progressively into the likeness of God and ultimately into the fullness of the divine presence.

A simple image may help before we go further. Think of a piece of iron placed in a fire. The iron does not become fire. It remains iron, with all the properties of iron: its weight, its density, its form. But as it sits in the fire, the fire enters it. The iron becomes hot, glowing, radiant with the heat and light of the fire that surrounds it. To look at the iron in that state is almost to see fire. And yet the iron has not ceased to be iron. It is iron, fully and completely, and at the same time it is filled with the fire’s own heat and light.

The Fathers, and particularly St. Ephrem the Syrian, use images very like this to describe theosis. The human person, placed in the presence of God through the life of the Church and the sacraments, does not cease to be human. But the divine life enters that human person, fills them, transforms them from within, so that gradually, by grace, they begin to shine with a light that is not their own, a warmth that comes from the fire of the divine love itself. This is theosis. This is what the Christian life is ultimately for. And as we are about to see, it is a thoroughly and irreducibly Trinitarian event from beginning to end.

Why Theosis is Trinitarian

Here is the claim at the heart of this post: theosis is not something the Trinity does for us from a distance. It is the Trinity drawing us into the relations that the three persons eternally share.

Consider the shape of it. In Holy Baptism and Holy Chrismation, the Holy Spirit comes to dwell in us. The Spirit, dwelling in us, unites us to the Son, making us members of His body and giving us the right to call God our Father with the Son’s own word, “Abba”. And the Son, having united us to Himself, presents us to the Father, so that the love with which the Father eternally loves the Son now rests on us as well. Jesus prays exactly this in John 17, that the disciples may be one “as you, Father, are in me and I in you, that they also may be in us,” and that “the love with which you have loved me may be in them.”

Notice what this means. Salvation is not a legal transaction conducted outside of God’s own life. It is adoption into that life. The Spirit brings us to the Son, the Son brings us to the Father, and the Father’s love returns through the Son and in the Spirit to fill us. The undivided light of the Trinity, which has been the theme of this whole series, is not only something to be contemplated. It is something to be entered.

This is why the fourth century controversies we studied in earlier posts mattered so desperately. If the Son were a creature, as Arius said, then union with the Son would only unite us to another creature, and no creature can deify. If the Spirit were a created force rather than fully God, then the Spirit’s indwelling would put something in us, but not God. The full divinity of the Son and the Spirit is the load-bearing wall of the whole house. Athanasius saw this with total clarity when he wrote that the Word became man so that we might become god, and his entire case against Arius rested on it. Only God can give God.

Athanasius of Alexandria: The Exchange That Makes Theosis Possible

We have already met Athanasius in the third post of this series, where we looked at his argument in “On the Incarnation” that only the eternal Son, truly God and not a creature, could accomplish what the Incarnation needed to accomplish. Now we return to him for the full soteriological/salvific implication of that argument, because Athanasius does not simply say that the Son became human in order to forgive sins or to defeat death, though he says both those things as well. He says something more radical: that the Son became human in order to make humanity capable of participating in the divine life.

The statement we began this post with, “He became human so that we might become divine,” appears in “On the Incarnation” and is repeated with slight variations in several of Athanasius’s later writings. In its context, it is not a rhetorical flourish. It is the precise and considered conclusion of a carefully constructed argument about why the Incarnation had to happen the way it did, and what it was designed to accomplish.

Athanasius’s argument runs like this. Humanity was created in the image of God, oriented toward God, sustained by the presence of the divine Word within human nature. When humanity turned away from God and toward the perishable, the divine image began to deteriorate. The orientation toward God was lost. Death, corruption, and the progressive diminishment of the human person set in. What was needed was not simply an external rescue, a pardon issued from a distance. What was needed was a renewal of the divine image within human nature itself, from the inside, by the One who is Himself the eternal Image of the Father, the eternal Son.

This is why the Son became human. Not merely to teach, not merely to set an example, not merely to provide a sacrifice, though all of these are real dimensions of what the Incarnation accomplished. The Son became human because only by entering human nature could He renew the divine image within it. The divine life, the eternal life of the Son who is of one being with the Father, entered human nature in the Incarnation, and in entering it, began the process of transforming it from within, restoring its orientation toward God, and opening it to the participation in divine life that is theosis.¹

Athanasius is clear that this transformation is not completed in the Incarnation (Birth of Jesus) alone. The Incarnation is the beginning. The death and resurrection of Christ are the turning point. The gift of the Spirit at Pentecost is the opening of the process to all believers. And the entire life of the Church, the sacraments, the scriptures, the community of prayer, is the ongoing context in which theosis takes place in the individual human person, over a lifetime, by grace.

What Athanasius gives us, then, is the foundational Trinitarian structure of theosis: the Father’s will and design, the Son’s entry into human nature to renew it from within, and the Spirit’s ongoing work of applying and completing that renewal in each believer. Theosis is not a human achievement. It is a divine gift, given by the Father, accomplished by the Son, and administered by the Spirit, to the human person who receives it through faith and the sacramental life of the Church.

Cyril of Alexandria: Participation Through the Son in the Spirit

Cyril of Alexandria, who has been present in almost every post of this series, is the theologian who develops the most systematic and detailed account of theosis in the Oriental Orthodox tradition. His understanding of theosis is grounded in his Trinitarian theology, his Christology, and his sacramental theology, and the three cannot be separated from one another in his thought. What Athanasius stated in its foundational form, Cyril worked out in its full implications.

Cyril of Alexandria explains theosis through the concept of participation (methexis). Human beings are drawn into the divine life not by becoming God by nature, but by truly participating in God’s life through grace. This participation comes through the Son and in the Holy Spirit, bringing about a real transformation while preserving the distinction between Creator and creature. Commenting on John 1:12, Cyril carefully distinguishes Christ, who is Son by nature, from believers, who become children of God by participation in Him. The Only Begotten does not merely bestow an external gift of sonship; He shares Himself, drawing us into His own filial relationship with the Father.

Participation through the Son means that the only way a human person can enter the divine life is by being united to the eternal Son who has Himself taken human nature. The Son, as we saw in the third post of this series, is truly and fully God, sharing the one divine nature with the Father completely. When the human person is united to the Son, in baptism and nourished in the Eucharist, what they are united to is not a created intermediary but the divine life itself, embodied in the person of the Son who has made human nature his own. The union with the Son is therefore a union with the divine life, a genuine and real participation in what God is, given through the one who is both God and human.²

Participation in the Spirit means that this union is not merely a legal or external arrangement, a forensic declaration that the human person is now counted as righteous. It is an ontological reality, a real change in the inner constitution of the human person, accomplished by the indwelling of the Holy Spirit. Cyril reads Paul’s statement that believers are temples of the Holy Spirit with great seriousness: if the Spirit truly dwells within the believer, and if the Spirit is truly God, sharing the one divine nature with the Father and the Son, then the divine life is truly and really present within the believer. The transformation this produces is real, not merely symbolic.³

Cyril develops this most fully in his Commentary on John, particularly in his treatment of the Bread of Life discourse in John 6 and the promise of the Spirit in John 14 through 17. For Cyril, the Eucharist is the primary sacramental locus of theosis: when the believer receives the body and blood of Christ, they receive the life-giving flesh of the eternal Son, the flesh that is inseparable from the divine nature of the one who took it, and through it they receive the divine life itself. The Spirit Who descends at the epiclesis is the same Spirit who makes this reception possible and effective, taking what belongs to the Son and giving it to the believer, as Jesus promised in the farewell discourse.⁴

Cyril also makes a point about theosis that is worth holding onto carefully, because it prevents a misunderstanding that is easy to fall into. He insists that theosis is always and only by grace, never by nature. The human person does not have within themselves, by virtue of being human, the capacity for theosis. It is entirely and completely a gift of God. This is not a depressing limitation. It is a liberating truth. It means that theosis does not depend on the human person’s own achievement, spiritual capacity, or moral perfection. It depends on God’s generosity, God’s initiative, and God’s determination to give the divine life to those who receive it through faith and the sacraments. The most spiritually ordinary person who receives the Qurbana in faith is receiving exactly the same gift of divine life as the greatest saint. The gift is the same. What differs is the degree to which each person has been opened to receive what is given.⁵

Ephrem the Syrian: He Gave Us Divinity, We Gave Him Humanity

Ephrem the Syrian, the fourth-century poet and theologian of Nisibis whose voice has accompanied this entire series, gives us in a single phrase what Cyril takes many pages of careful argument to establish. The phrase is this:

“He gave us divinity, we gave him humanity.”

It is worth staying with that for a moment, because it is one of those sentences that looks simple and turns out, the more you look at it, to contain almost the entire Gospel.

He gave us divinity. Not a share in some lesser spiritual reality. Not an improvement on the natural human condition. Not a religious experience or a spiritual feeling. Divinity itself, the life that God lives by nature, given to human beings by grace. This is what the Incarnation opened. This is what the Spirit pours into human hearts at Pentecost and in baptism and at every epiclesis of the Qurbana. This is what theosis means: divinity, given.

We gave him humanity. The Son took from us our nature, our flesh, our mortality, our capacity for suffering. He did not borrow it temporarily and return it unchanged. He took it and made it his own permanently, carrying it through death and resurrection and ascension into the very presence of the Father, where human nature now sits at the right hand of God, in the person of the eternal Son who has made it his forever.

The exchange is total. He gave everything He had by nature. We gave everything we had by nature. And the result is that the human person, united to the Son who has taken human nature into the divine life, now has access to that divine life from within. The exchange is not equal in the sense that we had anything to offer God that God needed. But it is complete in the sense that nothing is held back on either side.⁶

Ephrem develops this exchange theology in his Hymns on the Nativity, where he meditates at length on the mystery of the eternal Son entering the womb of Mary and taking human flesh. For Ephrem, the Nativity is not simply a beautiful story about a baby in a manger. It is the moment when the exchange began: when the eternal Son, who is the divine fire itself, wrapped himself in the cold of human flesh, so that human flesh might eventually be warmed by the divine fire from within.

Ephrem also connects theosis directly to the Eucharist in a way that has become one of the most celebrated passages in his writing. He speaks of the Eucharist as the medicine of life, the fire of the divine love placed on human lips, the burning coal from the altar of the Trinity given into human hands. When the faithful receive the Qurbana, they are receiving the flesh of the one who has exchanged divinity for humanity, and in receiving it, they receive divinity back. The exchange that began in the Nativity is completed, for each individual believer, at every celebration of the Eucharist.⁷

There is a tenderness in Ephrem’s account of theosis that is worth noticing, because it is easy for discussions of deification to become abstract and impersonal. Ephrem never allows that to happen. For him, theosis is always about love: the love of the Father who planned the exchange before time began, the love of the Son who willingly entered human flesh to accomplish it, and the love of the Spirit who brings that love home to the heart of each believer. The divine life that is given in theosis is not a substance or a quality. It is a relationship. And a relationship always has a face.

Severus of Antioch: Theosis in the Sacramental Life of the Church

Severus of Antioch, the sixth-century Patriarch of Antioch whose careful theological work we looked at in the previous post on Syriac Trinitarian vocabulary, brings to the theology of theosis a dimension that is perhaps the most practically important of all: the connection between theosis and the concrete, communal, sacramental life of the Church.

Severus is very clear in his Cathedral Homilies that theosis is not a private spiritual experience available to individual believers apart from the community of the Church and its sacramental life. It is something that happens within the Church, through the Church, and in the specific context of the Church’s liturgical and sacramental practice. This is a point that deserves emphasis, because there is a tendency in some forms of contemporary spirituality to treat the goal of the Christian life as a personal mystical experience that is essentially independent of community, institution, and sacrament. Severus would not recognise this as theosis. For him, the life of God is given through the specific, concrete, embodied means that the Church has received from Christ: baptism, the Eucharist, the community of prayer, and the ongoing life of worship.⁸

Severus pays particular attention to the role of the epiclesis, the invocation of the Holy Spirit during the Qurbana, in the theology of theosis. The epiclesis is the moment when the priest asks the Father to send the Holy Spirit upon the bread and wine of the Eucharist, to make them the body and blood of Christ, and to make their reception the gift of divine life to those who receive them. For Severus, this prayer is not a liturgical formality. It is the Trinitarian structure of theosis made visible and enacted in real time.⁹

Think about the structure of the epiclesis. It is addressed to the Father. It asks for the sending of the Spirit. And it is directed toward the Son’s body and blood on the altar, whose reception by the faithful is the gift of participation in the Son’s divine life. Father, Spirit, Son: the three persons of the Trinity all present and active in a single liturgical moment, each in their own way, together accomplishing in the life of the gathered community what the entire theology of theosis describes in the life of the individual believer.

Severus also connects theosis to the doxologies that structure the Qurbana and the daily offices of the Shehimo. When the Church sings “Subaho Labo Labro Vala Rooho Kadeesho,” (“Glory to the Father and to the Son and to the Holy Spirit”) it is not simply performing a religious duty or filling time between other elements of the service. It is enacting theosis in the mode of praise. The community that gives glory to the Trinity is, in that very act of praise, participating in the life of the Trinity: drawn by the Spirit into union with the Son, offering through the Son the praise that returns to the Father. The doxology is not a description of theosis. It is a participation in it.

There is a point Severus makes in one of his Cathedral Homilies that I have found personally striking and that I want to share here, even at the risk of being too personal for a series that is trying to maintain some theological rigour. Severus says that the goal of the Eucharist is not simply that the believer would receive something from God. The goal is that the believer and God would receive one another. The communion is mutual. God gives Himself to the human person in the Qurbana. And the human person, in receiving the Qurbana in faith, gives themselves to God. This is the exchange that Ephrem described in his phrase about divinity and humanity, enacted sacramentally at every celebration of the Eucharist. Theosis is not a one-directional transaction. It is a relationship of mutual self-giving, between the God who has always been a communion of love and the human person who has been created and redeemed to enter that communion.¹⁰

The Trinitarian Shape of Theosis

We have now heard four voices on theosis, and it is worth pausing to see what they, taken together, reveal about the Trinitarian structure of the life they are describing.

Theosis begins with the Father. It is the Father’s will, as Athanasius makes clear, that human beings created in the divine image should be restored to participation in the divine life from which they have fallen. The initiative comes from the Father. The plan is the Father’s. The desire to give human beings a share in the divine life is the Father’s desire, expressed before time began and enacted in time through the gift of the Son and the Spirit.

Theosis is accomplished by the Son. It is the Son’s entry into human nature, His taking of human flesh, His death and resurrection, that make theosis possible for human beings. Not by providing an example to follow or a legal mechanism to satisfy, but by actually uniting human nature to the divine life in his own person, so that what is true of the Son, the possession of the divine life, can be shared with those who are united to the Son. As Cyril insists, the human person’s participation in the divine life is always through the Son, because it is the Son who has made human nature the place where the divine life can be received.

Theosis is applied and completed by the Spirit. It is the Spirit who takes what belongs to the Son and brings it into the innermost life of the believer, who makes the union with the Son a real and personal reality within the human person rather than an abstract theological status, who prays within the believer and draws the believer progressively deeper into the divine life that the Son has opened. As Severus makes clear, this work of the Spirit happens specifically within the sacramental and communal life of the Church, through the epiclesis, through the Eucharist, through the daily offices of prayer.

And the goal of theosis, the destination toward which the entire movement is directed, is the Father. As the Son returns to the Father and sits at the Father’s right hand, carrying human nature into the divine presence, so the believer united to the Son is drawn toward the same destination: not the extinction of the human person in an undifferentiated divine absolute, but the arrival of the human person, fully and gloriously themselves, into the presence of the Father whose image they were created to bear and whose life they were created to share.

Theosis is, in its structure, nothing other than the shape of God’s own Trinitarian life, extended outward to include the human person. The Father who eternally gives himself to the Son, the Son who eternally receives from the Father and gives back in the Spirit, the Spirit who eternally proceeds from the Father and rests in the Son: this eternal movement of self-giving love now opens outward, through the Incarnation, the cross, the resurrection, and the gift of the Spirit, to include the human person in its own unending circulation of love.

The Malankara Qurbana: Theosis Enacted every Sunday

For those of us who worship in the Malankara Orthodox tradition, this theology is not distant or abstract. It is enacted in our midst every time the Qurbana is celebrated.

The opening prayers of the Qurbana address the Father. The readings and the sermon open the word of the Son to the community. The epiclesis invokes the Spirit upon the gifts. And then the faithful come forward to receive the Body and Blood of the eternal Son, in Whose flesh the divine life is given to human hands and placed on human lips.

This is the exchange Ephrem described, made real and present and available on an ordinary Sunday morning in an ordinary church. “He gave us divinity, we gave him humanity.” The divinity He gave us is on the altar. The humanity we gave Him is in the pews, coming forward to receive what He offered.

The communion prayers of the Malankara Qurbana, prayed by the faithful as they come forward to receive, carry a depth of theotic theology that most of us have perhaps never fully heard. The prayers speak of receiving the body and blood of Christ not as a memorial or a symbol but as the living presence of the one who has united humanity and divinity in His own person, and who now extends that union to the one who receives Him in faith.

What can be said with confidence, because it is consistent across the entire West Syriac liturgical tradition, is that the Malankara Qurbana is structured as a theotic event from beginning to end. The community that gathers for the Qurbana is not gathering to observe a religious ritual or to fulfil a religious obligation. It is gathering to be drawn, again and again, into the Trinitarian life of the God who made it and redeemed it. Every epiclesis is an invitation. Every reception of communion is a participation. Every doxology is a foretaste of the eternal praise that is the fullness of theosis: the human person, finally and completely filled with the divine life, returning to the Father in the Son and through the Spirit, the exchange complete, the undivided life received.

Why Theosis Changes Everything

It is tempting, at the end of a post this long and this theologically dense, to offer a simple practical takeaway. But theosis resists that kind of reduction. It is not a technique or a method or a spiritual practice we can add to our routine. It is the entire goal of the Christian life, the reason the Trinity acted in history, the reason the Son became human, the reason the Spirit was given at Pentecost.

What it does change is the framework within which everything else in the Christian life is understood. Prayer is no longer simply asking God for things. It is participation in the divine conversation of Father, Son, and Spirit, carried into that conversation by the Spirit who prays within us. The Qurbana is no longer simply a religious duty fulfilled weekly. It is the primary locus where the exchange Ephrem described takes place: divinity given, humanity received, the human person drawn progressively deeper into the life of the God who made them and loves them. Suffering is no longer simply something to be endured or escaped. It is, as both Ephrem and Severus make clear in different ways, a participation in the humanity that the Son took upon himself, and therefore a point of contact with the divine life that the Son brought to that humanity.

And the community of the Church is no longer simply an organisation that provides religious services. It is the community of those in whom theosis is taking place, the body of Christ in the world, the place where the divine life given at Pentecost is being poured out continuously through the sacraments, the scriptures, and the common life of prayer. To belong to the Church is to be enrolled in the school of theosis, learning, week by week and year by year, to receive more fully the life that is already being given.

Ephrem’s phrase stays with me as I write this, and I hope it stays with you as you read it.

He gave us divinity. We gave him humanity.

That is the entire Gospel in seven words. And if this series has done anything useful at all, I hope it has helped to show that this exchange has a shape, a grammar, and a name: the Trinity, the undivided life, the source and goal of everything.

A Prayer to Close

Father, you willed from before time that human beings should share in the life you share with your Son and your Spirit. Son, you became human so that we might become divine, taking our nature into yours and carrying it through death into the glory of the Father. Holy Spirit, you dwell within us as the gift of Pentecost, drawing us progressively deeper into the life that Father and Son share, making us by grace what God is by nature. We receive this gift with gratitude too large for words. Let the Qurbana we share, the prayers we offer, and the lives we live be, in your mercy, the ongoing enactment of the exchange you have begun in us. He gave us divinity. We gave him humanity. Let that exchange be complete in us, in your time and by your grace. Amen.

Next Wednesday: The final post in The Undivided Light series. Praying the Trinity, Doxology, Qurbana, and the Life of Worship. We will look at how the Trinity is encountered in the Church’s prayer life and what it means, practically and spiritually, to live as people drawn into the undivided life of Father, Son, and Holy Spirit.

This series, The Undivided Light, is an observational study, the reflections of someone sitting with these texts and trying to share what he is finding along the way. It is offered in humility, not as finished scholarship. If you are reading this, your prayers for the completion of the series are genuinely asked and gratefully received.

Sources and References

Khaled Anatolios, “Athanasius: The Coherence of His Thought” provides the most thorough analysis in English of the theotic structure of Athanasius’s soteriology and its Trinitarian grounding. ↩︎
Daniel A. Keating, “The Appropriation of Divine Life in Cyril of Alexandria”. This is the authoritative study of Cyril’s theology of participation and the most important secondary source for this section of the post. ↩︎
Norman Russell, “The Doctrine of Deification in the Greek Patristic Tradition”. ↩︎
David R. Maxwell, “Cyril of Alexandria: Commentary on John,” for Cyril’s Eucharistic theology and its connection to participation in the divine life. ↩︎
Thomas G. Weinandy and Daniel A. Keating, “The Theology of St Cyril of Alexandria: A Critical Appreciation”. The essay by Daniel Keating, “Cyril of Alexandria on the Unity of God,” on the distinction between deification by grace and divinity by nature in Cyril’s theology. ↩︎
Sebastian Brock, “The Harp of the Spirit: Eighteen Poems of Saint Ephrem,” on Ephrem’s exchange theology and its relationship to his Incarnational thought. ↩︎
Sebastian Brock, “Fire from Heaven: From Abel’s Sacrifice to the Eucharist,” on Ephrem’s Eucharistic theology and the image of the burning coal from Isaiah 6 as a type of the body and blood of Christ. ↩︎
Pauline Allen and C. T. R. Hayward, “Severus of Antioch,” The Early Church Fathers series, on Severus’s connection between the sacramental life of the Church and the process of deification in his Cathedral Homilies. ↩︎
Fr. Baby Varghese, “West Syrian Liturgical Theology” Chapter 6, “The Epiclesis and the Role of the Holy Spirit,” on the Trinitarian structure of the epiclesis in the West Syriac tradition and its theotic significance as understood by Severus and later Syriac theologians. ↩︎
Iain R. Torrance, “Christology after Chalcedon: Severus of Antioch and Sergius the Monophysite”, Chapter 5, “The Eucharist and Union with God,” on Severus’s theology of mutual self-giving in the Eucharist and its connection to theosis. ↩︎

The Undivided Light: The Holy Trinity (Part 6 of 7)