Answer
According to their claims, the Orthodox Church is the one church founded in AD 33 by Jesus Christ and His apostles on the day of Pentecost (Acts 2). The word Orthodox is derived from the Greek orthos, “right”; and doxa, “teaching” or “worship.” Worldwide, the Orthodox Church is estimated at 200 million members or more; the Orthodox Church is also known as the Eastern Orthodox Church, the Greek Orthodox Church, the Orthodox Catholic Church, and the Orthodox Christian Church.
The Orthodox Church believes its doctrine is that which was delivered by Christ to the apostles, as per Jude 1:3. The Orthodox Church’s primary statement of faith is the Nicene-Constantinopolitan Creed of 381.
Orthodox Church historians teach the Church of Alexandria was founded by Mark, the Church of Antioch by Paul, the Church of Jerusalem by Peter and James, the Church of Rome by Peter and Paul, and the Church of Constantinople by Andrew. These five churches represent the patriarchates of the Orthodox Church. Emperor Justinian I (AD 527—565) proposed a system of ecclesiastical government, naming Rome, Constantinople, Alexandria, Antioch, and Jerusalem as the pentarchy. Justinian’s system was later ratified at the Council of Trullo in AD 692. Today, the Patriarchate of Constantinople (renamed Istanbul in 1930) is the Ecumenical Patriarchate and holds the status of “first among equals.”
The Persecution of the Early Church
The Book of Acts chronicles the intense persecution faced by early believers, yet Christianity continued to spread across Europe, Asia, and Africa. During the first three centuries, the gospel of Jesus Christ withstood fierce opposition, particularly from tyrannical Roman emperors, and Christians lived in the shadow of death. Many persecuted believers gathered in catacombs, and Christian leaders such as Ignatius, Polycarp, Justin, and Cyprian were martyred.
Constantine
In 312, Emperor Constantine, claiming to have seen a vision of a cross with the inscription “In this sign conquer,” became the first Roman emperor to embrace Christianity. The following year, Emperor Constantine and Emperor Licinius issued the Edict of Milan, which ended Christian persecution within the Roman Empire. Half a century later, Emperor Theodosius outlawed paganism while making Christianity the only state-sanctioned religion in the Roman Empire.
In 324, Emperor Constantine moved his imperial capital from Rome to Byzantium, a city in eastern Greece on the Strait of Bosporus. In this transfer of power, Rome lost a measure of influence and prestige to Byzantium. Renamed in honor of the emperor, Constantinople became the seat of world power and the capital of Christendom. In 325, Constantine summoned church bishops to the Greek city of Nicaea for what was to be the first of seven ecumenical councils that would further shape church history.
The Seven Ecumenical Councils
Employing the council held in Jerusalem (Acts 15) as a model for settling doctrinal and disciplinary issues, seven assemblies of church leaders met from 325 to 787. The highlights of these councils are as follows:
The Council of Nicea I (325) condemned the heresy of Arianism and summarized the teaching of the apostles in credal form.
The Council of Constantinople I (381) expanded the Nicene Creed and reaffirmed teachings concerning the Holy Spirit and the doctrine of the Trinity. Like the first council in 325, this council condemned heretical teachers who were waging war against the Bible’s trinitarian teachings. The council also proclaimed Constantinople as the “New Rome.”
The Council of Ephesus (431) denounced another heretical teaching, Nestorianism. The council also discussed the Virgin Mary’s title of Theotokos, that is, the “Birthgiver of God.”
The Council of Chalcedon (451) anathematized monophysitism. The council also assigned equal honor to the Church of Constantinople and the Church of Rome and gave the title “patriarch” to the most prominent bishops. These decisions widened the rift between Rome in the West and Constantinople in the East.
The Council of Constantinople II (553) met to reaffirm that Jesus Christ, the Son of God, is one and the same divine Person (hypostasis) who united personally (hypostatically) in Himself the two natures of God and Man, without fusing them together and without allowing their separation. Additionally, Origen’s teaching on the pre-existence of the soul was condemned.
The Council of Constantinople III (681) met to condemn the monothelite heresy, ruling that, as Christ has two natures, He also has two wills, one human and one divine.
The Council of Nicea II (787) affirmed the use of icons in worship, rejecting the view that the veneration of icons amounts to idolatry.
The Rise of Islam
The rapid expansion of Islam dealt a number of blows to the Orthodox Church. In 647, fifteen years following Mohammad’s death, Islamic invaders had overtaken Syria, Palestine, and Egypt. Fifty years later, Islamic troops had encamped outside the gates of Constantinople, though the city would stand until 1453. North Africa and Spain were the next to fall. Ultimately, the Byzantine Empire would lose the Patriarchates of Alexandria, Antioch, and Jerusalem to Islamic conquerors.
The Great Schism
In 1054, an irreconcilable split, known as the Great Schism, between Constantinople and Rome occurred. The Roman Catholic Church separated itself from the Orthodox Church primarily over the issues of papal authority and an addition to the Nicene Creed known as the filioque clause. The relationship between Constantinople and Rome had been deteriorating over many years, partly due to language and cultural differences, and these tensions were further aggravated by hostile Islamic forces that made travel between Greece and Italy difficult. The sacking of Constantinople by Roman Crusaders in 1204 drove the two factions even further apart. Attempts at reunification, most notably the Council of Lyons in 1274 and the Council of Florence in 1438, were unsuccessful.
The Fall of Constantinople and Islamic Oppression
In 1453, Constantinople fell to the forces of Turkish sultan Mohammad II. For nearly five centuries, the Greek-speaking Christians struggled under the yoke of Islam. With Constantinople under Islamic rule, the Orthodox Church’s seat of authority shifted northward to Russia.
Today, the Eastern Orthodox Church exists as a family of thirteen self-governing bodies, denominated by the nation in which they are located (e.g., the Greek Orthodox Church, the Russian Orthodox Church, etc.). Separate from Eastern Orthodoxy is the Oriental Orthodox Church, a family of six self-governing church bodies. The Oriental Orthodox Church was begun as an offshoot of Eastern Orthodoxy in AD 451 and accepts only the first three of the ecumenical councils.
The Orthodox Church in America
Recognized as one of the four major faiths in America, the Orthodox Church has five million members who are grouped in over a dozen ecclesiastical jurisdictions. With about 500 parishes, the Greek Orthodox Archdiocese also operates schools, an orphanage, a college, and a graduate theological school. The Orthodox Church believes life begins at conception and thus opposes abortion on demand; additionally, the Orthodox Church maintains marriage is between one man and one woman and does not recognize same-sex marriages. Unlike the Roman Catholic Church, Orthodox Church priests may marry and raise families.
As the United States becomes increasingly secular, the Orthodox Church in America has suffered a decline in membership. Due to variances in reporting methods, the extent of the losses is unknown. Even so, some parishes are reporting an increase in membership, and the Orthodox Church is expected remain an influential force in American Christianity.