That the writers of the Bible recognized a plurality of gods -- were polytheists -- is proved by the following 'And the Lord God said, Behold, the man is become as one of us' (Gen. iii, 22). 'Who is like unto thee, O Lord, among the gods?' (Ex. xv, 11.) 'Among the gods, there is none like unto thee, O Lord' (Ps. Ixxxvi, 8). 'The Lord is a great God, and a great king above all gods' (Ps. xcv, 3). 'Thou shalt not revile the gods' (Ex. xxii, 28).Monotheism, the doctrine of one god, is not merely the worship of one god, but the belief in the existence of one god only. Many were monotheistic in worship -- worshiped one god, their national deity -- while at the same time they were polytheistic in belief -- believed in the existence of many gods. The Jews who worshiped Jehovah have been called monotheists. And yet, for a thousand years, they believed in the existence of Kemosh, Baal, Moloch, Tammuz, and other deities. They believed that Jehovah was their national god and that they owed allegiance to him; just as the subjects of an earthly king profess their loyalty to him without denying the existence of other kings.
~ John E. Remsburg