Judaism and Christianity differed markedly from Greco-Roman religious traditions. Judaism and Christianity were monotheistic, meaning they believed only one God ruled the universe. Greco-Roman faiths, in contrast, were polytheistic and henotheistic. Polytheism accepts the existence of multiple gods. Henotheism says that gods are local: different gods protect different geographical areas. Under henotheism, if a person moves from a certain area, he or she loses the protection of that god.
Greco-Roman religions were inclusive about religion, meaning they accepted religious pluralism and the power of more than one god. Jews and Christians were exclusive, meaning that adherence to either faith meant rejecting all other gods as false.
Greco-Roman gods were not expected to be particularly moral. One prayed and sacrificed to them to earn protection from harm and good fortune. The Judeo-Christian god, in contrast, was a moral god, a god who was expected to bring justice to the earth. In Christianity, internal moral behavior was expected: the religion emphasized internal transformation into a more loving and forgiving person as a chief manifestation of faith. Greco-Roman faiths, in contrast, demanded outward adherence to religious rituals as the means of purification and becoming right with the gods.
In the Greco-Roman world, the head of household, or paterfamilias, functioned as the priest, and the rest of the household—women, children, and slaves—followed his religious traditions. Judaism and Christianity had a separate priesthood. Jews and Christians were also sometimes considered to value women more highly than the wider culture, and did not, as a rule, practice infanticide.