The Anglican Communion is the third largest Christian communion after the Roman Catholic and Eastern Orthodox churches. Founded in 1867 in London, the communion has more than 85 million members within the Church of England and other autocephalous national and regional churches in full communion. The traditional origins of Anglican doctrine are summarised in the Thirty-nine Articles (1571). The archbishop of Canterbury in England acts as a focus of unity, recognised as primus inter pares, but does not exercise authority in Anglican provinces outside of the Church of England. Most, but not all, member churches of the communion are the historic national or regional Anglican churches.
Christianity is an Abrahamic monotheistic religion based on the life and teachings of Jesus Christ. It is the world's largest and most widespread religion with roughly 2.4 billion followers, comprising around 31.2% of the world population. Its adherents, known as Christians, are estimated to make up a majority of the population in 157 countries and territories. Christians believe that Jesus Christ is the Son of God, whose coming as the Messiah was prophesied in the Hebrew Bible and chronicled in the New Testament.
Eastern Christianity comprises Christian traditions and church families that originally developed during classical and late antiquity in Western Asia, Asia Minor, Eastern Europe, Southeastern Europe, the Caucasus, Northeast Africa, the Fertile Crescent and the Malabar coast of South Asia, and ephemerally parts of Persia, Central Asia and the Far East. The term does not describe a single communion or religious denomination.
Chalcedonian Christianity is a term referring to the branches of Christianity that accept and uphold theological resolutions of the Council of Chalcedon, the fourth ecumenical council, held in 451. Chalcedonian Christianity accepts the Christological Definition of Chalcedon, a Christian doctrine concerning the union of two natures 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.
Autocephaly is the status of a hierarchical Christian church whose head bishop does not report to any higher-ranking bishop. The term is primarily used in Eastern Orthodox and Oriental Orthodox Churches. The status has been compared with that of the churches (provinces) within the Anglican Communion.
Ecumenism – also called interdenominationalism, or ecumenicalism – is the concept and principle that Christians who belong to different Christian denominations should work together to develop closer relationships among their churches and promote Christian unity. The adjective ecumenical is thus applied to any non-denominational initiative that encourages greater cooperation and union among Christian denominations and churches.
Greek Orthodox Church is a Christian term that can refer to any one of three classes of church, each associated in some way with Greek Christianity or the Eastern Roman Empire.
A Christian denomination is a distinct religious body within Christianity that comprises all church congregations of the same kind, identifiable by traits such as a name, particular history, organization, leadership, theological doctrine, worship style and, sometimes, a founder. It is a secular and neutral term, generally used to denote any established Christian church. Unlike a cult or sect, a denomination is usually seen as part of the Christian religious mainstream. Most Christian denominations refer to themselves as churches, whereas some newer ones tend to interchangeably use the terms churches, assemblies, fellowships, etc. Divisions between one group and another are defined by authority and doctrine; issues such as the nature of Jesus, the authority of apostolic succession, biblical hermeneutics, theology, ecclesiology, eschatology, and papal primacy may separate one denomination from another. Groups of denominations—often sharing broadly similar beliefs, practices, and historical ties—are sometimes known as "branches of Christianity". These branches differ in many ways, especially through differences in practices and belief.
The East–West Schism, also known as the Great Schism or the Schism of 1054, is the break of communion between the Catholic and Eastern Orthodox churches since 1054. A series of ecclesiastical differences and theological disputes between the Greek East and Latin West preceded the formal split that occurred in 1054. Prominent among these were the procession of the Holy Spirit (Filioque), whether leavened or unleavened bread should be used in the Eucharist, iconoclasm, the coronation of Charlemagne as Emperor of the Romans in 800, the Pope's claim to universal jurisdiction, and the place of the See of Constantinople in relation to the pentarchy.
In Christian theology, ecclesiology is the study of the Church, the origins of Christianity, its relationship to Jesus, its role in salvation, its polity, its discipline, its eschatology, and its leadership.
Catholicity is a concept of pertaining to beliefs and practices that are widely accepted by numerous Christian denominations, most notably by those Christian denominations that describe themselves as catholic in accordance with the Four Marks of the Church, as expressed in the Nicene Creed formulated at the First Council of Constantinople in 381: "[I believe] in one, holy, catholic, and apostolic Church." The English adjective catholic is derived from the Ancient Greek adjective καθολικός, meaning "general", "universal". Thus, "catholic" means that in the Church the wholeness of the Christian faith, full and complete, all-embracing, and with nothing lacking, is proclaimed to all people without excluding any part of the faith or any class or group of people. An early definition for what is "catholic" was summarized in what is known as the Vincentian Canon in the 5th century Commonitory: "what has been believed everywhere, always, and by all."
The Catholic Church has engaged in the modern ecumenical movement especially since the Second Vatican Council (1962–1965) and the issuing of the decree Unitatis redintegratio and the declaration Dignitatis humanae. It was at the Council that the Pontifical Council for Promoting Christian Unity was created. Those outside of the Catholic Church were categorised as heretics or schismatics, but in many contexts today, to avoid offence, the euphemism "separated brethren" is used.
Ecclesiastical polity is the government of a church. There are local (congregational) forms of organization as well as denominational. A church's polity may describe its ministerial offices or an authority structure between churches. Polity relates closely to ecclesiology, the theological study of the church.
Branch theory is an ecclesiological proposition that the One, Holy, Catholic, and Apostolic Church includes various different Christian denominations whether in formal communion or not. The theory is often incorporated in the Protestant notion of an invisible Christian Church structure binding them together.
A schism is a division between people, usually belonging to an organization, movement, or religious denomination. The word is most frequently applied to a split in what had previously been a single religious body, such as the Great East–West Schism or the Western Schism. It is also used of a split within a non-religious organization or movement or, more broadly, of a separation between two or more people, be it brothers, friends, lovers, etc.
The term Eastern Protestant Christianity encompasses a range of heterogeneous Protestant Christian denominations that developed outside of the Occident, from the latter half of the nineteenth century, and yet retain certain elements of Eastern Christianity. Some of these denominations came into existence when active Protestant churches adopted reformational variants of Eastern and Oriental Orthodox liturgy and worship, while others are the result of reformations of Orthodox beliefs and practices, inspired by the teachings of Western Protestant missionaries.
Heresy is any belief or theory that is strongly at variance with established beliefs or customs, particularly the accepted beliefs or religious law of a religious organization. A heretic is a proponent of heresy.
In the year before the Council of Constantinople in 381, the Trinitarian version of Christianity became the official religion of the Roman Empire when Emperor Theodosius I issued the Edict of Thessalonica in 380, which recognized the catholic orthodoxy of Nicene Christians as the Roman Empire's state religion. Historians refer to the Nicene church associated with emperors in a variety of ways: as the catholic church, the orthodox church, the imperial church, the imperial Roman church, or the Byzantine church, although some of those terms are also used for wider communions extending outside the Roman Empire. The Eastern Orthodox Church, Oriental Orthodoxy, and the Catholic Church all claim to stand in continuity from the Nicene church to which Theodosius granted recognition.
