Eastern Orthodoxy

The second-largest Christian tradition, with approximately 220 million members, primarily in Eastern Europe, Greece, and Russia. Eastern Orthodoxy emphasizes continuity with the early church, mystical theology, liturgical worship, and the veneration of icons.

Core Beliefs

Theosis (Deification)

Orthodox theology centers on humanity’s participation in the divine nature through union with God. As the early church fathers taught, “God became man so that man might become god”—not in essence, but through grace and communion.

The Trinity

Like other Christians, Orthodox believers affirm the Trinity but emphasize the mystery and incomprehensibility of God’s nature. The Holy Spirit proceeds from the Father alone (rejecting the Western “filioque” clause that caused theological controversy).

Icons and Sacred Tradition

Icons are considered windows to heaven and are venerated (not worshiped) as means of encountering divine reality. Sacred Tradition, preserved through the councils, liturgy, and church fathers, carries equal authority with Scripture.

Seven Sacraments

Orthodox Christianity recognizes seven “mysteries”: Baptism, Chrismation (Confirmation), Eucharist, Confession, Holy Orders, Marriage, and Anointing of the Sick. Infants receive all three sacraments of initiation (baptism, chrismation, and communion).

Historical Development

• 1st-4th centuries - Establishment of church in apostolic sees
• 4th-8th centuries - Seven Ecumenical Councils define doctrine
• 8th-9th centuries - Iconoclastic controversy; icons affirmed
• 11th century - Great Schism (1054) separates East from West over papal authority and filioque clause
• 15th century - Fall of Constantinople (1453); center shifts to Russia
• 20th century - Persecution under communism; diaspora to West

Practices

Divine Liturgy

The central worship service, typically the Liturgy of St. John Chrysostom, is celebrated with elaborate ritual, incense, and chanting. The Eucharist is understood as the true body and blood of Christ.

Fasting

Strict fasting disciplines mark preparation for major feasts, with Orthodox Christians abstaining from meat, dairy, and fish during Lent and other fasting seasons.

Monasticism

Monastic communities, especially Mount Athos in Greece, preserve intense prayer traditions including the Jesus Prayer (“Lord Jesus Christ, Son of God, have mercy on me, a sinner”).

Church Structure

Unlike Roman Catholicism, Orthodoxy has no single head. Instead, it comprises autonomous (autocephalous) churches—Greek, Russian, Serbian, etc.—in communion with each other. The Ecumenical Patriarch of Constantinople holds a position of honor but not jurisdictional authority.

Geographic Distribution

Orthodoxy predominates in Greece, Russia, Ukraine, Romania, Serbia, Bulgaria, and other Eastern European nations. Significant diaspora communities exist in North America and Western Europe.

Relation to Other Christian Traditions

The Great Schism of 1054 divided Orthodoxy from Roman Catholicism over papal supremacy, the filioque, and other issues. While sharing apostolic succession and sacramental theology with Catholicism, Orthodoxy maintains distinct liturgical and theological traditions. Orthodox Christians view Protestantism as departing from apostolic tradition.