Eastern Orthodox

Eastern Orthodoxy traces its roots to the apostolic churches of the Eastern Roman, or Byzantine, Empire, including Constantinople, Antioch, Jerusalem, and Alexandria. For centuries these churches shared communion with Rome, developing a shared theology through ecumenical councils held between the 4th and 8th centuries. Growing disagreements over papal authority, liturgical practice, and a doctrinal addition to the Nicene Creed culminated in the Great Schism of 1054, dividing Christianity's East and West. Orthodoxy spread through Eastern Europe, Russia, and the Middle East, remaining organized as a communion of independent national churches.

Key figures: Saint Basil the Great, Saint John Chrysostom, Patriarch Photios I, Saint Vladimir of Kiev.

Eastern Orthodox Christians affirm the Nicene Creed, the Trinity, and the incarnation, death, and resurrection of Christ, understanding salvation as a lifelong process of theosis, becoming more like God through grace, prayer, and participation in the sacraments, called mysteries. Orthodoxy places heavy emphasis on the decisions of the seven ecumenical councils of the early church and on unbroken tradition passed down from the apostles, viewed as inseparable from scripture rather than a secondary source alongside it. Authority rests not in a single leader but in the consensus of bishops and the whole believing community across history.

Icons, sacred images of Christ, Mary, and the saints, hold a central theological place, understood as windows into the divine rather than mere art, and are venerated in worship. The Divine Liturgy, largely unchanged for over a thousand years, is the heart of Orthodox worship, filled with chant, incense, and elaborate ritual. Orthodoxy rejects the filioque clause added to the Creed in the West and does not recognize the Pope's universal jurisdiction, instead honoring the Patriarch of Constantinople as first among equals.

• No single global leader; a communion of self-governing churches
• Central place of icons in worship and theology
• Theosis: salvation as becoming like God
• Unbroken Divine Liturgy tradition
• Married parish clergy permitted
• Rejects the filioque clause and papal supremacy

Orthodox worship centers on the Divine Liturgy, a lengthy, sensory-rich service filled with chanting, incense, candles, and elaborate ritual, typically celebrated standing. Church interiors are covered in icons, and a screen called the iconostasis separates the altar area from the congregation. Services are often conducted in a church's traditional liturgical language, whether Greek, Church Slavonic, Arabic, or others, though English-language parishes are common in the West.

Eastern Orthodoxy has no single earthly head. It is a communion of autocephalous, or self-governing, national churches, such as the Greek, Russian, Serbian, and Antiochian Orthodox churches, each led by its own patriarch or archbishop. The Ecumenical Patriarch of Constantinople holds a symbolic primacy of honor but not governing authority over the other churches, which are doctrinally united but administratively independent.

Eastern Orthodoxy shares ancient roots, the seven sacraments, and much theology with Roman Catholicism, but rejects papal supremacy and the filioque clause, and organizes as independent national churches rather than a single hierarchy. Compared to most Protestant traditions, Orthodoxy retains a strong sacramental and liturgical life, venerates icons and saints, and holds tradition and scripture as inseparable rather than emphasizing scripture alone. Orthodox theology also frames salvation more as transformative union with God than as a legal verdict, a differing emphasis from many Western traditions.

Compare it with the full family of traditions on the Christian denominations overview, take the denomination quiz to see which fits you, or look up any unfamiliar term in the Christian glossary.

Eastern Orthodoxy counts roughly 220 to 260 million adherents worldwide, concentrated in Eastern Europe, Russia, Greece, and the Middle East, making it the second-largest organized Christian communion.