When and how did the Schism between the Western Catholic and the Eastern Orthodox Churches take place? The West commonly associates it with an incident in 1054 CE. Of the many points of difference and dispute between East and West in 1054, only two remain current: the ultimate theological authority of either ecumenical councils or the papacy, and the West’s insertion of the filioque (“and the Son”) into the Niceno-Constantinopolitan Creed of 381 CE. This chapter discusses both the origin of the filioque and the subsequent rise of monarchic papal authority in the West. The insertion of the filioque is sometimes incorrectly attributed to the Third Council of Toledo (589 CE), but it was definitively added to the creed by the Carolingians at a council in Aachen in 809 CE in close association with Charlemagne’s claim to be the only legitimate Roman emperor, and that change in the creed prevailed despite opposition at the time by Pope Leo III.

In this chapter, I argue for an account of worship as real union. To worship the Divine is to participate in the goodness of God, in an ontological way. But how can we really participate in God? The answer depends on the coherence of an important distinction between the essence and divine energies of God. We cannot participate in the essence of God, otherwise the distinction between creature and creator breaks down. Rather, we participate in the divine energies of God. Although there is a difference between the divine essence and the divine energies, the divine energies are not something distinct from God. God interacts with us and reveals himself to us through the divine energies. The divine energies are the activities of God that can penetrate our inner being and change us from potentially being good to actually being good. Thus, worship, in the proper and strict sense, divinizes us.

In the first section of this chapter, I critique Rudolf Bultmann’s emphasis on stripping away the ‘mythological’ apparel of the Gospels in order to access something behind or beneath the New Testament text by suggesting a way of reading that leaves the mythos intact and able to ‘speak’ on its own terms. In the second section, I suggest how Jesus’ own myth-making is inseparably bound up in his identity and the emergence of God’s presence in history, appealing to the work of Eberhard Jüngel and Hans Urs von Balthasar to re-place the kerygma inside the mythos itself as a ‘quasi-sacramental’ presentation of the divine.

John Keble and his protégé Charlotte Yonge take ritual time in a seemingly humbler, domestic direction. Rather than using higher time to engage an overarching political project as Wordsworth did with the Revolution, they see the church calendar as sacralizing even the smallest mundane tasks – the trivial round, as Keble calls it. Yet, for Keble, the transfiguration of daily work performed in linear time leads to nothing less than humanity’s deification or theosis, to use the language of the Greek Church Fathers venerated by the Oxford Movement. For Yonge, higher time and the Prayer Book’s liturgies not only reconcile reason and faith but also structure the material work of parish reform – the building of a local school, the repair of a dilapidated neighborhood, the hiring of a responsible priest to replace an absentee one. Through liturgy, therefore, the Tractarians can attend to everyday life while still seeing that life as sharing in the divine.

The first chapter explores the meaning of religion - which is much broader than the belief-system of any given ecclesial communion - and also the meaning of theosis in its early historical development. Religion is considered up to the early modern age but theosis only to the end of the patristic age as the springboard for the study of later developments as they relate to religion.

The second chapter traces the post-patristic career of theosis in the Byzantine world from its role in the promotion of Chalcedonian Christology in the sixth century through to the definition (at the Constantinopolitan Council of 1351) of theosis as participation in the uncreated energies. A postscript explains why the Byzantine tradition was taken up in modern times not by the Greeks but by the Russians.

The Afterword summarises the previous seven chapters, arguing that theosis is not a gnostic type of spiritualisation that de-creates us but the bringing of creation as a whole to its ultimate fulfilment.

The sixth chapter examines the patristic revivals of theosis in the early twentieth century by the Russian émigré theologians of the ’Paris School’, principally through the work of Myrrha Lot-Borodine, Vladimir Lossky, and the later Bulgakov. The first two of these writers engage with modern theologians partly to differentiate Orthodoxy from its new Catholic environment and partly (especially in Lossky’s case) to enable Western theology to enrich itself through interacting with Orthodox thinking.

The Introduction surveys the different meanings of theosis and religion that have evolved over the centuries as a way of defining the book’s principal terms. Then after discussing the recent debate about whether theosis is a doctrine or a theological theme, it introduces the subsequent chapters as an exercise in intellectual history. The narrative thread of this history is provided by the different receptions of Dionysius the Areopagite in Eastern and Western Christianity. Theosis emerges as a polyseme, its meaning defined by the different contexts in which it is used.

One important reason why Tolstoi so fiercely rejected Orthodox dogmatics was that he considered a purely theoretical approach to faith, disconnected from the lives of the believers, to be useless. Therefore, he had far greater sympathy with the Orthodox mystic-ascetic devotional literature associated with the so-called Hesychast movement. Chapter 4 analyzes Tolstoi’s exposure to this Orthodox monastic spirituality and how it influenced his thinking. He had a well-thumbed copy of Philokalia (Dobrotoliubie), a basic text of Orthodox spirituality and the most important of the Hesychast writings. Here, Tolstoi found confirmation of his strongly negative views of the body and the passions. The Philokalia taught that we should not merely control but indeed extinguish our passions. Passionlessness, apatheia – a concept also found among the Stoics and in Buddhism – should be the aim of the Christian life. This was an ideal that Tolstoi preached and which informed many of his views, on the necessity of physical labor, nonresistance to evil, and abstention from property, drugs, alcohol and even sex. Moreover, also Tolstoi’s claim that the essence of human life is not only spiritual but divine has a clear affinity with the Orthodox doctrine of theosis, the deification of man.