Christianity is an Abrahamic, monotheistic religion based on the life and oral teachings of Jesus of Nazareth as presented in the New Testament. Christianity is the world's largest religion, with about 2.4 billion adherents, known as Christians. Christians believe that Jesus has a "unique significance" in the world. Most Christians believe that Jesus is the Son of God, fully divine and fully human, and the saviour of humanity whose coming was prophesied in the Old Testament. Consequently, Christians refer to Jesus as Christ or the Messiah.
The foundations of Christian theology are expressed in ecumenical creeds. These professions of faith state that Jesus suffered, died, was buried, and was resurrected from the dead in order to grant eternal life to those who believe in him and trust in him for the remission of their sins. The creeds further maintain that Jesus bodily ascended into heaven, where he reigns with God the Father. Most Christian denominations teach that Jesus will return to judge everybody, living and dead, and to grant eternal life to his followers. He is considered the model of a virtuous life. His ministry, crucifixion, and resurrection are often referred to as "the gospel", meaning "good news" (a loan translation of the Template:Lang-grc-gre). The term gospel also refers to written accounts of Jesus's life and teaching, four of whichTemplate:Snd the Gospels of Matthew, Mark, Luke, and JohnTemplate:Snd are considered canonical and included in Christian Bibles.
Christianity began as a Second Temple Judaic sect in the mid-1st century. Originating in the Levant region of the Middle East, it quickly spread to Europe, Syria, Mesopotamia, Asia Minor, and Egypt. It grew in size and influence over a few centuries, and by the end of the 4th century had become the official state church of the Roman Empire, replacing other forms of religion practiced under Roman rule. During the Middle Ages, most of the remainder of Europe was Christianized, and adherents were gained in the Middle East, North Africa, Ethiopia, and parts of India. Following the Age of Discovery, Christianity spread to the Americas, Australasia, sub-Saharan Africa, and the rest of the world through missionary work and colonization. Christianity has played a prominent role in the shaping of Western civilization.
Worldwide, the three largest groups of Christianity are the Catholic Church, the Eastern Orthodox Church, and the various denominations of Protestantism. The Roman Catholic and Eastern Orthodox patriarchates split from one another in the schism of the 11th century, and Protestantism came into existence during the Reformation of the 16th century, splitting from the Roman Catholic Church.