Eastern Orthodoxy comprises the faith and practices stemming from ancient churches in the eastern part of the Roman Empire. It encompasses Orthodox churches in communion with the see of Constantinople.
The Orthodox, Catholic, Apostolic Church is the direct descendant of the Byzantine state church and consists of independent national churches that are united by doctrine, liturgy, and hierarchical organization (church leaders include deacons and priests, who may either be married or be monks before ordination, and bishops, who must be celibates). The heads of these churches are called patriarchs or metropolitans. Rivalry between the pope of Rome and the patriarch of Constantinople, as well as differences that existed for centuries between the eastern and western parts of the empire, led to a schism in 1054. The mutual excommunication pronounced in that year was lifted in 1965, however, and a climate of better understanding has ensued. Orthodox churches belong to the World Council of Churches.
The Eastern Orthodox churches recognize only the canons of the seven ecumenical councils (325–787) as binding for faith, and they reject doctrines that have been added in the West.
The central worship service is called the Liturgy, which is understood as representing God's acts of salvation. Its center is the celebration of the Eucharist, or Lord's Supper. Icons (sacred pictures) have a special place in Orthodox worship. The mother of Christ, angels, and saints are venerated. The Orthodox Church and the Western Catholic Church recognize the same number of sacraments.
Orthodox churches are found in Greece, Turkey, Russia, the Balkans, and other parts of the former Soviet Union. In this century Orthodox faith has spread to western Europe and other parts of the world, particularly North America.