means ' One truth and multiple ways of acheiving it '. Thats what hinduism is all about. we do beleive in one supreme god. but we also beleive that there are multiple ways of worship. and one way is to worship the different facets of the supreme god.( to personify individual characteristics/powers of the supreme god as individual gods ). whats wrong in that ? did ur prophet prove that there is only one god ? he just made a statement.So its just a theory. even worshipping idols is a theory.both theories are at the same level,bcos both are scientifically unproven.
