Christianity is a monotheistic religion centered on the life and teachings of Jesus of Nazareth as recounted in the Gospels. Christians believe Jesus to be the son of God and refered to as the Messiah, and called formally as Jesus, the Christ or Jesus Christ. With an estimated 2.1 billion adherents in 2001, Christianity is the world's largest religion. In the New Testament, the term "Christian" first appears in Acts:11:26–31: "The disciples were called Christians first at Antioch." (Greek accusative Χριστιανούς; Christianous).