Christianity arose out of Judaism: Jewish tradition was that a Messiah would come and for Christians, this was Jesus. For Jews (and later Muslims), he was not, though I think all accept him as a prophet - just not the son of God.
The oldest religions were to do with the forces of nature - weather, death, fertility (of people and the land), things people couldn't understand or explain were attributed to supernatural beings. The earliest god was probably the earth mother, thought to be responsible for crops growing, on which human life depended. She was gradually surrounded by other gods, as in Greece and Rome, particularly male ones (you can see organised religion, run by males, taking over here) and her role diminished to that of lesser goddesses like Diana or Isis. Adoration of the Virgin Mary is probably a distant descendant of worship of the Goddess.