The primordial religion of India was polytheistic, as other early religions all over the world. Many of the gods were animistic (associated with animals and objects), as in most early religions and in the semi-Catholic cult of saint-worshippers. Hinduism developed from this as a semi-monotheistic religion believing in "atman," the universal oneness. Siva, the god of destruction and creation and remover of boundaries, is, like all other gods, avatars, humans, rocks, and everything else, just a facet of atman. Siva is no more a name for G-d than the Holy Spirit--Siva is a facet of atman just as the Spirit is a facet of the HolyTrinity
developed Buddhism from Hinduism in an analogous fashion to Christ developing Christianity from Judaism.