It was a belief in spirits and multiple gods that was before the belief in one god. But native american believe in what they call a creator. This is quite common in many old religions and "extinct" religions. Also it was very usual that people mixed their relgions with others from people they've met. Like the vikings when they came to egypt, they borught home some religious ideas from there.
- Science is not trying to create an answer like religion, it tries to find an answer.