The Bible. Topical Bible Studies. Topical Index. Christianity. Christianity is an Abrahamic religion that began as a Jewish sect in the mid-1st century.[9][10] Originating in the Levant region of the Middle East, it quickly spread to 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.[11] 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.[12][13] 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.[14][15][16] Christianity has played a prominent role in the shaping of Western civilization.[17][18][19][20][21] Beliefs Creeds.