Spirit is exactly a word derived etymologicaly from root and very ancient origins to be no more than the air we breath literally.
I've already shown and given you research to show it was much more complicated than that. If you want to push your view over and over, that's fine. It's incorrect and lazy to do so without showing your supporting evidence, but you can, of course, do so.
At the end of the day, though, it's a metaphor.