The Orthodox Church is the Church founded by Christ, the New Testament Church continued through the ages. She fully identifies herself with the One Holy Catholic and Apostolic Church. Since ancient times she calls herself Orthodox, which means “right-believing”, in order to separate herself from the heretical churches (Arian, Nestorian, Monophysite, etc.). The Church came to be called Orthodox especially after the iconoclastic period.
The Orthodox Church although one in faith and worship is comprised of eighteen churches administered independently. They are: The four ancient patriarchates of Constantinople, Alexandria, Antioch, Jerusalem and the ancient Church of Cyprus; the eight national autocephalous churches of Russia, Greece, Serbia, Romania, and Bulgaria, Georgia, Albania and Poland; and five autonomous churches of Czechoslovakia, Finland, Japan, China and the Church of Mount Sinai (consisting of St. Catherine’s monastery). The total number of Orthodox Christians in the world is estimated at 225 million, of which about six million are in the U.S.A. and Canada. The orthodox churches in America are not entirely self-governing, but depend on their respective “mother churches”. The Ecumenical patriarchate has not accepted the autocephaly granted to O.C.A. by the patriarchate of Moscow.
The Assyrian (Nestorian) and Oriental Orthodox (Monophysite) churches split from Eastern Orthodoxy after the Councils of Ephesus (431) and Chalcedon (451) respectively. The latter, comprising the Armenian, Coptic, Ethiopian, Jacobite and Syro-Malabar churches (known collectively as the Oriental Orthodox churches), did not accept the formula of the Council of Chalcedon that Christ is in two natures, human and divine, and condemned the bishop of Rome Leo as a heretic. Today steps are being taken to reconcile the differences between the two bodies of churches.
The major split between East and West occurred in 1054. There were many factors that led to their final separation: political, cultural, social, linguistic and theological. The doctrines of “filioque” (meaning “and from the Son”), the primacy of the pope of Rome and Purgatory remain as the main reasons of the continuous separation. Finally, the fate of the great schism was sealed by the sack of Constantinople by the crusaders in 1204.
The Orthodox Church accepts that the Holy Spirit proceeds from the Father only, just as she accepts that the Son is generated from the Father only, thus recognizing the Father as the only source of divinity.
The Orthodox Church rejects the primacy and infallibility of the pope of Rome, accepting instead a conciliar form of Church government, with all bishops being equal, while certain bishops are held in greater honor. It is the entire Church that is led to the truth by the Holy Spirit. The pronouncements of ecumenical councils enjoy a status of infallibility as pertains to faith and morals.
Also the Orthodox Church has never accepted the Roman Catholic teachings of Purgatory (understood as an intermediate state with a purifying fire), the indulgences, the Immaculate Conception of the holy Virgin, created grace, divine satisfaction, rationalism, original sin (as an inheritance of the sin and guilt of Adam and Eve), baptism (by sprinkling), use of statues, forced celibacy of clergy, and many other innovations.
The Orthodox Church equally rejects innumerable Protestant false teachings, like putting Scripture in place of the Church (“the pillar and foundation of the truth”), rejection of holy Tradition, of apostolic succession, of ordained priesthood, of the veneration of the Virgin Mary (“all generations shall call me blessed”) and of the Saints (“blessed are the dead who die in the Lord”), of the real presence in the holy Eucharist, etc., etc., etc.
The Orthodox Church accepts only the Nicene Creed. The official version of the Old Testament she follows is the Septuagint (the Greek translation, which includes the deuterocanonical books, written in the original Greek). The New Testament was written entirely in Greek, and is the same one followed by Roman Catholicism and Protestantism.
Mystery and beauty receive as much emphasis in the Orthodox Church as do doctrine and dogma. The icons have religious status as objects of veneration, as do the symbol of the holy cross, the book of the holy gospel and the relics of the Martyrs and other Saints.
Orthodoxy stresses participation in the sacramental life of the Church, monasticism and ascetical practices. Fasting is followed on every Wednesday and Friday, limiting consumption of food and abstention from fatty foods (meats, milk products, eggs, fish, olive oil) and during four main fasting seasons throughout the year (Easter, Christmas, Feast of the Mother of God and Feast of the Holy Apostles).
The Orthodox people follow two different calendars: the old Julian and the more accurate Gregorian, followed by the west. The Slavic churches, the patriarchate of Jerusalem, Mount Athos and other smaller communities follow the old calendar, which lags 13 days behind the Gregorian one. They celebrate Christmas on the seventh of January. Pascha (Easter), which is considered the highest Christian feast, is held based on the old calendar, thus all Orthodox people celebrate Easter together.