Hey! Sorry for the delay on this -- to count as a god, they have to have been worshipped in their own right. For example, Hercules was worshipped as a protector of mankind in ancient Greece, with his main temple in Thebes, and was a favorite god of athletes, so, as a deified hero, he would be considered appable as a god.

The concept of "god" is often different in different religions' theologies, but in general, a being that is worshipped independently and is seen as being a figure of power in their own right (as opposed to a particularly devout human, like saints or prophets in Christian theology) would count.