Theosis
Authors: Foltz Bruce V. 
Published: January 2012

Theosis is the Greek term, central to patristic theology, that is usually translated as “deification,” and perhaps better but less often as “divinization”: it means to become, through grace, what God is by nature. It has certain similarities to the western notion of sanctification, although it is much more deeply transformative. It also has certain similarities to what in the West came to be called “mystical union,” but in the patristic literature, and as it continued to be understood in the Greek East, theosis was not seen as exceptional, something reserved for the few in whom it was supernaturally “infused,” but rather as what should be the central dynamic in the process of salvation for each person. The concept has Biblical origins, as is most clearly evident in the injunction in the Second Epistle of Peter to “become partakers of the divine nature” (1:4). In the Gospel of St. John, too, Christ invites us to “abide” in him, joined together with him as branch to vine (15:1–11). St. Paul states that we are the holy temple of the “Spirit of God,” in whom God dwells (1 Cor. 3:16, 17), exclaiming that “not I, but Christ liveth within me” (Gal. 2:20). And emphasizing the ultimately eschatological context for theosis in its fullest sense, the First Epistle of John declares that “we shall be like Him, for we shall see Him as He is” (3:2). In the patristic literature, the Christocentric dimension of theosis is emphasized. St. Irenaeus says that the Word “became what we are in order to make us what he is,” and St. Athanasius says that “God became man in order that man might become God.” St. John of Damascus connects the two terms with an analogy: just as the flesh of Christ became deified through union with his person through “the operation of divine grace,” like iron becoming fire “not by its own nature, but by being united, burned, and mingled with fire,” so too through being “filled with the Holy Spirit” the saints become deified as well, becoming God not by nature, but by grace (First Apology, 1:19). St. Macarius understands this dynamically, as initiated from the side of God: “In His clemency and His love for men He transforms Himself, incarnate Himself, mingles Himself with the holy, pious and faithful ones, becomes ‘one spirit’ with them according to Paul (1 Cor. 6:17)” (Hom. XVII, 3). Nor is this merely a divinization of the soul alone, but of the body as well, which does not cease to be deified after death (ibid.). Thus, the universal veneration of incorrupt relics in traditional Christianity is based not on superstition and credulity, but upon the theology of theosis as a divinizing of the whole person, that continues to manifest itself after death, and thereby to give testimony of the triumph of Christ over it. Ultimately, the theology of theosis is dependent upon the distinction between the divine essence (
ousia
) and the divine energies (
energeia
), a distinction present with the Alexandrian and Cappadocian Fathers, but most clearly drawn later by St. Gregory Palamas. For theosis does not compromise divine transcendence, since the divine essence remains forever mysterious and unattainable, and it is with the divine energies or activities, God's communication of himself to us, which is nevertheless God, that we can be united. But the extent of theosis reaches even farther. To the degree that it is united with God though grace, humanity can extend the love of God to all creation, embrace it within this divine love, and thus become the agent through which creation itself becomes deified, a task for which humanity was originally created, but which it can now complete only to the extent that it is joined together with Christ, who himself has joined together ontologically humanity and divinity. Although theosis is usually associated with Orthodox Christianity, where its formative influence has been greatest, it has always had resonances in the West, especially in Latin tradition, although more recently it has begun to receive attention in Protestant circles as well.