Osiris, to go directly to the important part of this, was…

““Osiris, to go directly to the important part of this, was not a "dying god," not "life caught in the spell of death," or "a dead god," as modern interpreters have said. He was the hallucinated voice of a dead king whose admonitions could still carry weight. And since he could still be heard, there is no paradox in the fact that the body from which the voice once came should be mummified, with all the equipment of the tomb providing life's necessities: food, drink, slaves, women, the lot. There was no mysterious power that emanated from him; simply his remembered voice which appeared in hallucination to those who had known him and which could admonish or suggest even as it has before he stopped moving and breathing. And that various natural phenomena such as the whispering of waves could act as the cue for such hallucinations accounts for the belief that Osiris, or the king whose body has ceased to move and is in his mummy cloths, continues to control the flooding of the Nile. Further, the relationship between Horus and Osiris, 'embodied' in each new king and his dead father forever, can only be understood as the assimilation of an hallucinated advising voice into the king's own voice, which then would be repeated with the next generation.””

— Julian Jaynes