The central tenet of Christianity is the belief in Jesus as the Son of God and the Messiah (Christ). Christians believe that Jesus, as the Messiah, was anointed by God as savior of humanity, and hold that Jesus' coming was the fulfillment of messianic prophecies of the Old Testament.hristianity began as a Second Temple Judaic sect in the mid-1st century. Originating in Judea, it quickly spread to Europe, Syria, Mesopotamia, Asia Minor, Egypt, Ethiopia, and India and by the end of the 4th century had become the official state church of the Roman Empire.