Ecumenical council in the context of "Nicaea"

The Oriental Orthodox Churches are Eastern Christian churches adhering to Miaphysite Christology, with approximately 60 million members worldwide. However, the Oriental Orthodox Churches, individually, claim approximately 87 million baptized members. The Oriental Orthodox Churches adhere to the Nicene Christian tradition. Oriental Orthodoxy is one of the oldest branches in Christianity.

As some of the oldest religious institutions in the world, the Oriental Orthodox Churches have played a prominent role in the history and culture of countries and regions such as Armenia, Egypt, Eritrea, Ethiopia, Sudan, the Levant, Iraq and the Malabar region of southern India. As autocephalous churches, their bishops are equal by virtue of episcopal ordination. Their doctrines recognize only the first three ecumenical councils as valid.

Chalcedonian Christianity is the branch of Christianity that accepts and upholds theological resolutions of the Council of Chalcedon, the fourth ecumenical council, held in AD 451. Chalcedonian Christianity accepts the Christological Definition of Chalcedon, a Christian doctrine concerning the union of two natures (divine and human) in one hypostasis of Jesus Christ, who is thus acknowledged as a single person (prosopon). Chalcedonian Christianity also accepts the Chalcedonian confirmation of the Niceno-Constantinopolitan Creed, thus acknowledging the commitment of Chalcedonism to Nicene Christianity.

Chalcedonian Christology is upheld by Roman Catholicism, Eastern Orthodoxy, Lutheranism, Anglicanism and Calvinism (Reformed Christianity), thus comprising the overwhelming majority of Christianity.

The Council of Chalcedon (/kælˈsiːdən, ˈkælsɪdɒn/; Latin: Concilium Chalcedonense) was the fourth ecumenical council of the Christian Church. It was convoked by the Roman emperor Marcian. The council convened in the city of Chalcedon, Bithynia (modern-day Kadıköy, Istanbul, Turkey) from 8 October to 1 November 451. The council was attended by over 520 bishops or their representatives, making it the largest and best-documented of the first seven ecumenical councils. The principal purpose of the council was to re-assert the teachings of the ecumenical Council of Ephesus against the teachings of Eutyches and Nestorius. Such doctrines viewed Christ's divine and human natures as separate and distinct (Nestorianism), or viewed Christ as solely divine (monophysitism). The Council of Chalcedon issued the Chalcedonian Definition, stating that Jesus is "perfect both in deity and in humanness; this selfsame one is also actually God and actually man." The Council's judgments and definitions regarding the divine marked a significant turning point in the Christological debates.

The Council of Ephesus was a council of Christian bishops convened in Ephesus (near present-day Selçuk in Turkey) in AD 431 by the Roman Emperor Theodosius II. This third ecumenical council, an effort to attain consensus in the church through an assembly representing all of Christendom, confirmed the original Nicene Creed, and condemned the teachings of Nestorius, Patriarch of Constantinople, who preferred that the Virgin Mary be called Christotokos, "Christ-bearer" over Theotokos, "God-bearer"; in contrast to Cyril of Alexandria who deemed that Theotokos is enough on its own. It met from 22 June to 31 July 431 at the Church of Mary in Ephesus in Anatolia.

Lutheranism or Evangelical Lutheranism is a major branch of Protestantism that emerged under the work of Martin Luther, the 16th-century German friar and reformer whose efforts to reform the theology and practices of the Catholic Church launched the Reformation in 1517. The Lutheran Churches adhere to the Bible and the Ecumenical Creeds, with Lutheran doctrine being explicated in the Book of Concord. Lutherans hold themselves to be in continuity with the apostolic church and affirm the writings of the Church Fathers and the first four ecumenical councils.

The schism between Roman Catholicism and Lutheranism, which was formalized in the Edict of Worms of 1521, centered on two points: the proper source of authority in the church, often called the formal principle of the Reformation, and the doctrine of justification, the material principle of Lutheran theology. Lutheranism advocates a doctrine of justification "by Grace alone through faith alone on the basis of Scripture alone", the doctrine that scripture is the final authority on all matters of faith. This contrasts with the belief of the Roman Catholic Church, defined at the Council of Trent, which contends that final authority comes from both Scripture and tradition. In Lutheranism, tradition is subordinate to Scripture and is cherished for its role in the proclamation of the Gospel.

The First Council of Nicaea (/naɪˈsiːə/ ny-SEE-ə; Ancient Greek: Σύνοδος τῆς Νικαίας, romanized: Sýnodos tês Nikaías) was a council of Christian bishops convened in the Bithynian city of Nicaea (now İznik, Turkey) by the Roman Emperor Constantine I. The Council of Nicaea met from May until the end of July 325.

This ecumenical council was the first of many efforts to attain consensus in the church through an assembly representing all Christendom. Hosius of Corduba may have presided over its deliberations. Attended by at least 200 bishops, its main accomplishments were the settlement of the Christological issue of the divine nature of God the Son and his relationship to God the Father, the construction of the first part of the Nicene Creed, the mandating of uniform observance of the date of Easter, and the promulgation of early canon law.

The First Council of Constantinople (Latin: Concilium Constantinopolitanum; Ancient Greek: Σύνοδος τῆς Κωνσταντινουπόλεως) was a council of Christian bishops convened in Constantinople (now Istanbul, Turkey) in AD 381 by the Roman Emperor Theodosius I. This second ecumenical council, an effort to attain consensus in the church through an assembly representing all of Christendom, except for the Western Church, confirmed the Nicene Creed, expanding the doctrine thereof to produce the Niceno-Constantinopolitan Creed, and dealt with sundry other matters. It met from May to July 381 in the Church of Hagia Irene and was affirmed as ecumenical in 451 at the Council of Chalcedon for Chalcedonian Christianity and the Second Council of Ephesus for the Oriental Orthodox Churches.