Christianity is based upon the life and teachings of Jesus Christ, whose life is written about in the New Testament. Jesus, a Jew, was born in about 7 B.C. and assumed his public life, probably sometime after he turned 30, in Galilee. The Gospels tell of many extraordinary deeds that accompanied his ministry. He proclaimed the kingdom of God and referred to himself as the Son of Man. Jesus set forth the religious and ethical demands for participation in the kingdom of God as a change of heart and repentance for sins, love of God and neighbor, and concern for justice.
Circa A.D. 30 he was executed on a cross in Jerusalem, a brutal form of punishment for those considered a political threat to the Roman Empire.
After his death his followers came to believe in him as the Christ, the Messiah. The Gospels report his resurrection, and the risen Jesus was witnessed by many of his followers. The apostle Paul helped spread the new faith in his missionary travels.
Historically, Christianity arose out of Judaism and claims that Jesus fulfilled many of the promises of the Hebrew Scripture (referred to by Christians as the Old Testament).
The new religion spread rapidly throughout the Roman Empire. In its first two centuries, Christianity began to take shape as an organization, developing distinctive doctrine (principles), liturgy (the form of its ceremonies), and ministry. By the fourth century the Catholic church had taken root in countries stretching from Spain in the West to Persia and India in the East. Christianity was proclaimed the state religion of Rome in 380. In 1054, the Christians of the East and West decided to separate their churches because of differing beliefs and a rivalry between the Pope of Rome and the Patriarch of Constantinople. The resulting churches were the Eastern Orthodox Church, based in Constantinople, and the Roman Catholic Church, based in Rome. The Reformation began in 1517, which ultimately caused a schism in the Western church. Reformers wished to change certain practices within the Roman church, but also came to view the Christian faith in a distinctly new way. The major Protestant denominations (Lutheran, Presbyterian, Reformed, and Anglican [Episcopalian]) thus came into being. Over the centuries, numerous denominations have broken with these major traditions, resulting in a wide variety of Christian expression. Through its missionary activity Christianity has spread to most parts of the globe.
Eastern Orthodoxy comprises the faith and practices stemming from ancient churches in the eastern part of the Roman Empire. It includes the Orthodox churches that are in communion with the office of the Bishop of Constantinople.
The Eastern Orthodox Church is descended from the Byzantine State Church. It is made up of many independent national churches that share the same doctrine (principles), liturgy (the form of ceremonies), general beliefs, and a hierarchy of church leaders. Orthodox churches belong to the World Council of Churches.
The Eastern Orthodox churches recognize only the canons of the seven ecumenical councils (325–787) as binding for faith, and they reject doctrines that have been added in the Western Church.
The central worship service is called the Liturgy, which is understood as representation of God's acts of salvation. Its center is the celebration of the Eucharist, or Lord's Supper. Icons (sacred pictures) have a special place in Orthodox worship. The Mother of Christ, angels, and saints are highly venerated. The Orthodox Church and the Western Catholic Church recognize the same number of sacraments.
Orthodox Churches are found in Greece, Turkey, Russia, the Balkans, and other parts of the former Soviet Union. In this century Orthodox faith has spread to western Europe and other parts of the world, particularly America.
The Roman Catholic Church functions under the authority of the bishop of Rome, the Pope, who is the spokesperson and representative of the bishops and all other Catholics. The pope, as the head of the hierarchy of archbishops, bishops, priests, and deacons, has full ecclesiastical power. The powers that others in the hierarchy possess are delegated. Roman Catholics believe their church to be the one, holy, catholic, and apostolic church, possessing all the properties of the one, true church of Christ.
The Roman Catholic faith is understood to be identical to the teachings of Christ and his apostles, which are contained in the Bible and traditional practices. The center of Roman Catholic worship is the celebration of the Mass, the Eucharist, which is the commemoration of Christ's sacrificial death and resurrection. Other sacraments are baptism, confirmation, penance, matrimony, anointing of the sick (formerly known as extreme unction), and holy orders. The Virgin Mary and the other saints and their relics are highly venerated.
The Roman Catholic Church is the largest Christian organization in the world, found in most countries. Vatican Council II (1962–65) sought to “update” the church, bringing about changes in practice and more deeply involving the laity. The immensely popular Pope John Paul II (1978–) has reached out to Catholics worldwide through his extensive travels.
Protestantism developed out of a movement in the 16th century that was called the Reformation. This movement tried to reform the Roman Catholic Church (that's why it was called the Reformation) and it resulted in the establishment of the Protestant churches. A monk named Martin Luther was the leader of the Reformation, and the name Protestant was originally given to his followers because they protested against a decree that forbade any further church reforms. Other influential reformers included John Calvin, Ulrich Zwingli, and John Knox. Protestantism rejected attempts to tie God's revelation to earthly institutions and strictly adhered to the Word of God as sole authority in matters of faith and practice (sola scriptura). The church is understood as a fellowship, and the priesthood of all believers is stressed.
The Augsburg Confession (1530) was the principal statement of Lutheran faith and practice. It became a model for other Protestant confessions of faith. Major Protestant denominations include the Lutheran, Reformed (Calvinist), Presbyterian, and Anglican (Episcopalian). Many sects and denominations have sprung from these roots, including Quakers, Baptists, Pentecostals, Congregationalists, Methodists, and nondenominational assemblies. Sects that have appeared in more modern times include Mormons, Christian Scientists, and Jehovah's Witnesses. Protestant missionary activity, particularly strong in the last century, resulted in the founding of many churches in Asia and Africa. The ecumenical movement, which originated with Protestant missions, aims at unity among Christians and churches.