ECUMENICAL COUNCILS

First Ecumenical Council - First Council of Nicea, A.D. 325

This council was called by the Roman Emperor Constantine the Great. It was in response to the heresy of Arianism, which said that Jesus was not divine, but merely human. The Nicean Council declared that Jesus was both human and divine and it denounced  Arianism as heresy. The Council also defined the first part of what would later be called the Nicene Creed. 318 bishops attended this Council.

Second Ecumenical Council - First Council of Constantinople, A.D. 381

This council was called by Roman Emperor Theodosius I. It was in response to the heresy of Macedonianism, which said the Holy Spirit was merely one of God’s powers and not a person like God the Father and God the Son. The Council defined the doctrine of the Holy Trinity: that God is three persons – God the Father, God the Son, and God the Holy Ghost. This doctrine along with other articles was added to the Nicene Creed. 150 bishops attended.

Third Ecumenical Council - Council of Ephesus, A.D. 431

This council was called by Byzantine Emperor Theodosius II, grandson of Theodosius I. It was in response to the heresy of Nestorianism, which said Jesus was merely a man in whom the Word of God dwelled (as in a temple). Nestorianism also taught that Mary, Jesus’ mother, was merely the mother of Christ, not to be called Mother of God. The Council declared that Jesus Christ is completely God and completely man (although without sin) and that Mary is rightly called the Mother of God. Furthermore, the Council declared that the Nicene Creed, defined during the first two Councils, was complete and never to be changed. 200 bishops attended.

Fourth Ecumenical Council - Council of Chalcedon, A.D. 451

This council was called by Byzantine Emperor Marcian. It was in response to the Monophysitism, which said Jesus’ human nature was transformed by his divine nature, making him divine and not human. The Council declared, as it did in previous councils, that Jesus was both fully human (though without sin) and divine. 630 bishops attended.

Fifth Ecumenical Council - Second Council of Constantinople, A.D. 553

This council was called by Byzantine Emperor Justinian the Great. It was called due to the persistence of the Nestorian and Monophysite heresies. The Council confirmed, again, the dual nature of Jesus Christ as both God and man. 165 bishops attended.

Sixth Ecumenical Council - Third Council of Constantinople, A.D. 680-681

This council was called by Byzantine Emperor Constantine IV. Like the previous Council, it was called to deal with the persistence of the heresies about the human and divine nature of Jesus Christ. The Council declared that Jesus was fully man and fully divine and that the two natures exist with “no confusion, no change, no separation, no division”. 170 bishops attended.

Seventh Ecumenical Council - Second Council of Nicea, A.D. 787

Called by the Byzantine Empress Irene, this Council considered the question of icons: art which depicted Jesus, the Father, the Holy Ghost, Mary, and the saints. This included crucifixes. Many Christians, particularly in the East, venerated icons. Others considered this to be idolatry and sought to destroy icons. These opponents are the source of today's word “iconoclasts” (Greek for “image destroyer”). The Council declared that religious icons are not idols, but only representations. Therefore icons could be used to venerate Father, Son and Holy Ghost, Mary, and the saints, and had to be respected. However, icons were not to be worshipped for themselves. 367 bishops attended.

Eight Council - Fourth Council of Constantinople, A.D. 879-880

Restored St. Photius the Great to his see in Constantinople and anathematized any who altered the Nicene-Constantinopolitan Creed, abrogating the decrees of the Robber Council of 869-870. This council was at first accepted as ecumenical by the West but later repudiated in favour of the robber council in 869-870 which had deposed Photius.

Ninth Council - Fifth Council of Constantinople, A.D. 1341-1351

Affirmed hesychastic (a mystical tradition of prayer in the Orthodox Church. It is described in great detail in the Philokalia, a compilation of what various saints wrote about prayer and the spiritual life) theology according to St. Gregory Palamas and condemned the Westernized philosopher Barlaam of Calabria.

 
These are the statements of faith defined by the Orthodox Church. Together with the Gospels and the Apostles’ Council of Jerusalem, they form the essential, shared faith of all orthodox Christians.

Nicene-Constantinople Creed

We believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible;
And in one Lord Jesus Christ, the Son of God, the Only-begotten, Begotten of the Father before all ages, Light of Light, Very God of Very God, Begotten, not made; of one essence with the Father; by whom all things were made:
Who for us men and for our salvation came down from heaven, and was incarnate of the Holy Spirit and the Virgin Mary, and was made man;
And was crucified also for us under Pontius Pilate, and suffered and was buried;
And the third day He rose again, according to the Scriptures;
And ascended into heaven, and sits at the right hand of the Father;
And He shall come again with glory to judge the living and the dead, Whose kingdom shall have no end.
And we believe in the Holy Spirit, the Lord, and Giver of Life, Who proceeds from the Father, Who with the Father and the Son together is worshipped and glorified, Who spoke by the Prophets;
And we believe in one, holy, catholic, and apostolic Church.
We acknowledge one Baptism for the remission of sins.
We look for the Resurrection of the dead,
And the Life of the age to come. Amen.

Note: The Nicene-Constantinopolitan Creed as it is recited in Orthodox worship today uses the first person ("I believe..."/"Πιστεύω") rather than the first person plural as it was enacted at the councils.

The Nicene-Constantinopolitan Creed (also called the Nicene Creed, the Symbol of Faith, the Pistevo, or simply the Creed) is that creed formulated at the First and Second Ecumenical Councils. It was defined by the Holy Fathers of those first two councils (held in Nicea and Constantinople, respectively) to combat various heresies: notably Arianism, Apollinarianism, Macedonianism (also called Pneumatomachianism), and Chiliasm.

Some scholars believe that the Creed promulgated by the First Ecumenical Council was based on an earlier baptismal creed used in Palestine (the Apostles' Creed), while others regard its more likely origin as being a creed issued early in A.D. 325 in Antioch, a so-called "Syrian Creed."

The Creed as it now stands was formed in two stages, and the one in use today in the Orthodox Church reflects the revisions and additions made at the Second Ecumenical Council. Some centuries later, the Roman Catholic Church attempted a unilateral revision of the Creed by the addition of the Filioque, thus being one of the causes of the Great Schism between Rome and the rest of the Church.

The Coptic church has a tradition that the Nicene Creed was authored by St. Athanasius of Alexandria, whose theology was instrumental at the Nicene council, despite his being only a deacon at the time.