The manga and anime never gave a clear explanation as to why he wasn't able to die. It did say he was a follower of Jashin or something like that that encourages mass murder, but it didn't actually say if his immortality was a product of his religion. however, if it is, does that mean that there are gods in the narutoverse? The third and the fourth were both able to summon actual shinigami and the tailed beasts are basically demons filled with chakra, but are there more supernatural beings and creatures guiding their world?
i know this is a funny question, but what i am getting at is what is the source of some of the characters' powers? If gods do exist in the narutoverse, does that mean that Pain's rinnegan powers are actually godly? is hidan's immortality from a god? if so, why didn't orochimaru just become a jashinist or steal the rinnegan from jiraiya's student or something?