What religious belief separated the Israelites from other groups in their geographic area?

Answer 1

Belief in One God.

Since the Hebrews and non-Hebrews lived side by side in their area, there may have been some borrowing in language or other minor matters. But in terms of fundamental beliefs, the two populations are quite different.Judaism, according to tradition, has always been monotheistic. Even at the height of the unfortunate spread of idolatry among the less-loyal Ten Tribes, there were thousands who remained loyal to God (1 Kings 19:18).

(See: Judaism and monotheism)

Others, however, believed in a number of deities, which sometimes led to aberrations in people's behavior (See: Cruelties of the polytheists). This was among the reasons why Abraham the Hebrew founded ethical monotheism.

It may be noted that there are certain comparative similarities that can be found among the ancient Hebrews and non-Hebrews. According to tradition, this did not stem from borrowing, but rather from the existence of an even older tradition; the worldwide one stemming from Noah. This is, for example, why (almost all) people over the entire world believed in the existence of the soul, the afterlife, the significance of the number seven, the institution of marriage, the abhorrence of cannibalism, etc.