> Can you please provide a citation to a mainstream Egyptologist
> who professes that Osiris actually "came into being as a
> mummified non existent being".
> I am unable to find one and yet your assertion suggests this
> belief is widespread "according to Egyptology".
Egyptologists believe that in the earliest incarnation of Osiris this was a "god" who was a "mummy". Yes, some believe he's modeled off of an earlier god or even possibly a man but "Osiris" is by definition a non-existent being whose earliest incarnation was as a mummified "thing". This mummified non-existent being oozed corpse drippings through which one must tip toe and had a very pleasing odor. He had evil comings and he was cool effervescent water. He smelled like his son "Horus", especially Horus's eye.
According to the translation of the PT this is the ancient Egyptian belief. Well... ...this... ...and they believed in magic. Each god and each proper noun has conflicting definitions and characteristics. Some of the funniest are "Horus" who was born with no feet and no arms but had a hundred legs. And could still manipulate things with his hands and all this despite being a bird.
This is what Egyptologists believe the PT actually means. They massage the words each year but you can't erase gobbledty gook from word soup. These are the beliefs upon which Egyptological understanding is based. They believe the authors of the PT had the same beliefs as the authors of the book of the dead with no evidence to support it. Based on this belief they interpret the entire culture most of which was found in tombs.
I believe the PT are misinterpreted because they were written in a different form of Egyptian than what Egytologists currently understand. They can't see this because they made the assumption that the great pyramid builders had the exact same beliefs as the writers of the book of the dead. I believe that when taken as a different language the PT actually makes perfect sense and has no scribal errors in it.