Christianity

Christianity is the largest religion in the world, with over two billion adherents, roughly one-third of humanity, and is made up of a large set of traditions originating in first-century Palestine with the philosophy and teachings of Jesus Christ. As an historical and theological offspring of Judaism, the early Christian community incorporated the Jewish scriptures into their Bible and the relationship between the Jewish and Christian traditions remains complex and multifaceted. Christianity is a monotheistic faith that teaches that God is made up of three persons sharing a single essence (this teaching is known as Trinitarianism), and that His will for the world has been revealed in the Bible, a book made up of several dozen pieces of literature composed over 2,000 years.

Theology

Christian theology is largely based upon several core beliefs:

God

Christianity is monotheistic; that is, Christians believe in one God, who is in three persons, the Father, Son, and Holy Spirit. This God is understood to be identical to the Jewish understanding of God in the earlier portions of the Bible. Christianity asserts that God is ethically perfect, or holy, and that God is immutable; that is, God does not change.

Christians believe that Jesus was the Son of God—the second person within the Trinity—and that he was both fully human and fully divine; he is considered to be God incarnate on the Earth.

Soteriology

Soteriology is the theology of salvation. Christians believe that, as a result of the fall of Adam and Eve, all humans are sinful. Because of this "sinful nature", all people are not in a proper relationship with God, possibly doomed to be condemned to Hell for breaking God's command.. However, Christian soteriology asserts that Christ came to Earth as a human being, and was crucified to take the punishment for man's sin. Christians believe that a person must accept God's forgiveness, and if they do so, that they are allowed to go to heaven.. Most Protestants today agree that salvation is "by grace alone", meaning that a person is not required to do good works to get into heaven, although good works will generally be a by-product of salvation.

Eschatology

Eschatology is the study of "last things," or beliefs about the end of the world and the afterlife. Christians believe that after Christ was crucified, he was resurrected from the dead (the origin of the celebration of Easter), that he ascended to Heaven, and he will return to Earth.

There is very wide disagreement among Christians about the Second Coming. The disagreement is on when exactly Christ will return to Earth, whether the book of Book of Revelation is primarily about past, current, or future events, or whether it should be interpreted as metaphor, and what social action Christians should take. The premillennialism school of thought, strongest in the 21st century among fundamentalists and evangelicals, holds that the second coming of Christ precedes and ushers in the millennium (the thousand years mentioned in Revelation 20 during which holiness is to be triumphant and Christ is to reign on earth). They argue that it can come at any moment, with portends indicating it may come soon. This position downplays social action because nothing mankind can do will hasten the Second Coming. In opposition the postmillennialism position holds that the second coming of Christ will be after the millennium which is to come as the result of the Christianization of the world without miraculous intervention. This position strongly encourages Christians to reform the world in order to hasten Christ's coming. Postmillennialism was a major source of social activism among Christians in the 19th and early 20th centuries, including the Second Great Awakening, the abolitionist movement, the Third Great Awakening and the Social Gospel movement. Mainstream Protestant denominations after 1920 downplayed the Second Coming.

A recurring theme in the history of Christianity is that, in every age, there are Christians who believe that the eschatological pronouncements of the Bible apply to that point in history. Interestingly, this tendency even existed with the earliest Christians. In 1 Corinthians 7, the apostle Paul urges his followers not to worry too much about their present state of affairs: "I mean, brothers and sisters, the appointed time has grown short... For the present form of the world is passing away" (1 Cor. 7:29-31, trans. NRSV)-- a statement most scholars take to mean that Paul believed the return of Christ (and perhaps the end of the world) was immanent.

Theological developments

Romanticism was a search for feeling and an exploration of the inner soul. Nowhere was this more true than in theology, where the German theologian Friedrich Schleiermacher (1768–1834) reshaped liberal Protestant thought. Traditionally theologians pondered the infinity and omnipotence of God. That was less relevant, argued Schleiermacher, than the inner feeling of a person of absolute dependence upon God, and the intuition of God's presence. Blessedness, he taught, consists in the strengthening of the God-consciousness through the community of believers (the Church); sin is the obscuring of this consciousness. Jesus Christ shared the humanity of all human beings but was unique in the strength and constancy of his God-consciousness.

Karl Barth reacted against 20th-century liberal thought and the innerness of God, and insisted on God's transcendence. Barth stressed the discontinuity between the Christian message and the world. God is the wholly other, He is known only in His revelation, and He is not the patron saint of culture, but its judge.

Denominational taxonomy

Christianity has developed into a variety of traditions and ecclesiastical bodies over the past 2,000 years. The broadest division is between Eastern and Western Christianity, two families that come from historical differences between the the Greek-speaking Byzantine Empire and Latin-speaking Roman Empire. The Eastern traditions are primarily made up of the Eastern Orthodox Church and the Oriental Orthodox Church, two associations of national churches in communion (although not with one another.) The Western faiths trace their heritage through direct descent, Reformation, or missionizing from the Roman church and include Catholicism, Protestantism, and Anglicanism, as well as a variety of splinter groups such as the Mormons.

In addition, there are hundreds of millions of independent Christians - many in the United States; sub-Saharan Africa, where the Pentecostal movement has been influential; and in mainland China - that have a legacy of some Protestant history, but are not formally associated with a church authority. Some churches from the East have formally joined the Catholic faith, and are historically and culturally Eastern, but ecclesiastically Western.

Eastern Christianity

Eastern Orthodox

The Eastern Orthodox Church is made up of approximately 17 national churches - the numbering can differ depending on one's perspective on the Orthodox Church in America. These national churches are all in communion with one another and none of them have any ecclesiastical authority over one another, although they all recognize the special place of the Ecumenical Patriarch of Constantinople as primus inter pares or "first among equals." These independent churches are called autocephalous and several smaller churches are autonomous and under the authority of autocephalous bodies.

Eastern Orthodoxy and Roman Catholicism were in communion with one another until the East-West Schism or Great Schism of 1054, in which the Ecumenical Patriarch and Pope excommunicated one another. The differences between the two bodies had been building for centuries: the East used Greek as a liturgical language, the West used Latin; Easterners emphasized monasticism, mysticism, and negative theology to experience God, whereas Westerners focused on rationalistic explanations and formalized doctrines.

Oriental Orthodox

The Oriental Orthodox Church is more loosely affiliated culturally than the Eastern Orthodox, but the role of the Coptic Pope is stronger ecclesiastically than the Ecumenical Patriarch. The Oriental Orthodox ceased to be in communion with the rest of Christianity after the Council of Chalcedon in 451 and the resulting Chalcedonian Creed which established a particular formula for understanding how Jesus can be both divine and human in full measure. The Christology of the Orientals has been labeled monophysite, but the Church defines itself as miaphysite - the differences go back to the original Christological controversy of the fifth century, with the former denying that Jesus had any substantial human nature. Similar to the Easterners, Orientals use icons in worship, have a strong monastic tradition, and have focused on the lives of saints for spiritual guidance.

Assyrian

The Assyrian Church of the East became a separate body after the Council of Ephesus in 431, a gathering of Christians to combat the heretical group lead by Nestorius. This was another Christological controversy and consequently, the Assyrians have been dubbed Nestorian by outsiders, but maintain that their understanding of Jesus' natures is not and has never been Nestorian. In the mid-sixteenth century, several churches broke communion with the Patriarch of Babylon, spiritual head of the Church of the East and joined into communion with the Catholic Church becoming the Eastern Catholic Chaldean Rite. Due to political instability in Iraq and Assyrian immigration, the church is headquartered in Chicago, the United States.

Eastern Rite

While the Latin Rite of Catholicism makes up over 98% of the believers in the Catholic Church, there are 15 Eastern Rites which are allowed to conduct their own liturgy and maintain many of their own distinct doctrines and practices while acknowledging the primacy of the Bishop of Rome, as an authoritative head to their church as well.

Western Christianity

Catholicism

Catholicism is the largest denominational family amongst Christians, and the Roman Catholic Church is the largest institution of any kind on the face of the Earth, largely due to missiological efforts in Latin America. In addition to believers who are the product of Portuguese and Spanish colonialism, Catholicism has a strong history in Western Europe, where it remained virtually the sole church in the West from the time of the Schism through the Reformations of the 15th and 16th centuries.

The Catholic Church is united by several distinct traditions, possibly the most important of which is the Pope - Bishop of Rome and the monarch of Vatican City. The Pope's ecclesiastical see is known as the Holy See and is given a priority in terms of both honor and authority amongst all other Catholic bishops. Catholics have rich traditions of doctrine, canon law, sainthood, and sacred architecture.

Protestantism

Protestantism is not a single church body or set of formally-related organizations, but a grouping of various church families whose history extends to the Reformations in 16th century Europe. The main families are the Lutheran, the Reformed and Presbyterians, and the Anabaptists. Protestantism has spread as widely across the globe as has Catholicism, and has developed into a wide variety of national expressions as well as being foundational in international ecumenical movements such as the World Council of Churches.

Certain pre-Reformation groups are frequently included in discussions about Protestantism, such as Waldensians and Moravians, who are legacies of reformation movements lead by Peter Waldo in 12th-century Italy and Jan Hus in 15th-century Bohemia. Some classification systems also include Anglicans as well, as the Church of England and the Roman Catholic Church ceased to be in communion roughly concurrent with the Reformation. Since the Reformation, large Protestant groups include Baptists, Methodists, the Disciples of Christ, and Adventist churches that come from the Restorationist movement of mid-18th century America. Some of most particular Christian groups come from the latter movement, including Mormons and the Jehovah's Witnesses. Depending on the definition of what constitutes Christianity, those movements may not even be considered Christian due to their unique understandings of virtually every Christian doctrine.

Anglicanism

Anglicanism is a form of Christianity with commonalities with both Protestantism and Catholicism. The Anglican Church was formed by Henry VIII at roughly the same time as the self-definition of Protestantism, and there are some commonalities between Protestantism and Anglicanism. The Church of England ceased to be in communion with Rome as a result of Henry's actions and his insistence that the King of England be head of the British church. At the same time, the emphasis on ritual and liturgy in the Roman Catholic Church is also found, to some extent, in the Anglican Church. Anglicans also stress the common lineage their clergy have with Catholics - a doctrine known as apostolic succession, which ties present-day religious workers with the original twelve apostles of Jesus.

Independent churches

Some churches that do not identify with any denomination. Charismatic Christianity and Pentecostalism are two similar movements founded in the twentieth century which prioritize an individual's experience of God through the Holy Spirit, including the reception of spiritual gifts such as glossolalia, spiritual healing, and prophecy. Charismatics have generally stayed within their original church bodies, whereas Pentecostals have created their own denominations and separate churches. These bodies are particularly prevalent in Africa.

Evangelicalism is another movement that exist both with established church groups and entirely independent churches, some of which have evolved out of small house churches and private Bible study groups into larger networks of churches, particularly in America. Evangelicals are similar to fundamentalists in some of their emphasis on the priority of the Bible, but are not as hostile to modernity nor mainstream politics. They have also been associated with a social Gospel in their insistence on providing services to underprivileged populations, particularly through missions work.

Both of these movements are Western although they have typically do not have formal ties to other historically Western churches.

Ecumenism

Another important cross-denominational movement in the 20th century has been ecumenism: a cooperation of Christian bodies that can be as simple as coordinating common efforts in social services, writing common theological statements, the restoration of communion between bodies, and even the creation of entirely new denominations themselves, such as the Uniting Churches. The World Council of Churches (WCC) is an international body whose membership includes a majority of the Christian world if one includes Catholicism (the Roman Catholic Church is not a member of the WCC, but works with it closely on several initiatives.) The National Council of Churches is an American equivalent that has similar goals as the WCC.