Christian Traditions: Orthodoxy, Catholicism, and the Reformation

Eastern Orthodox Christianity understands salvation chiefly in terms of theosis, or deification, the transformative process by which believers come to participate in the divine nature through grace, a concept rooted in the writings of Greek patristic theologians such as Athanasius of Alexandria and Gregory of Nyssa. Its worship centers on the Divine Liturgy, most commonly in the form associated with John Chrysostom, and on the veneration of icons, sacred images whose theological legitimacy was affirmed after a period of controversy at the Second Council of Nicaea in 787 CE. Organizationally, Orthodoxy is not governed by a single central authority but consists of a communion of self-governing, or autocephalous, churches, including the Church of Constantinople, the Russian Orthodox Church, and the Greek Orthodox Church among others, with the Ecumenical Patriarch of Constantinople honored as "first among equals" rather than as a supreme ruling authority. A distinctive strand of Orthodox spirituality, Hesychasm, a contemplative practice centered on inner stillness and the repeated Jesus Prayer, was defended theologically in the fourteenth century by Gregory Palamas against Western-influenced critics, and remains influential, particularly within Orthodox monasticism.