So this thought appeared to me recently, and I'd thought I would throw out there for your consideration. Others have probably written about this, and if you know of anyone else that has, please send me a link or a book title or whatever. I think the idea is simply stated, but very complex. Also I wonder that the consideration of such an idea could be very "enlightening" as far as the relationship between the physical and mental realities are concerned.
So lets start the title statement.
The word "God": Old English "supreme being, deity; the Christian God; image of a god; godlike person," from Proto-Germanic (source also of Old Saxon, Old Frisian, Dutch , Old High German , German , Old Norse , Gothic ), which is of uncertain origin; perhaps from PIE "that which is invoked" (source also of Old Church Slavonic "to call," Sanskrit "invoked," an epithet of Indra), from root "to call, invoke." The notion could be "divine entity summoned to a sacrifice."
Even the etymological roots of the word bring up some interesting anomalies.
Next is "egregore" (note that this is the simple Wikipedia definition. Root word analysis is not something I have access to at this point in time): is an occult concept representing a "thoughtform" or "collective group mind", an autonomous psychic entity made up of, and influencing, the thoughts of a group of people.
If I was to start the very conversation for the topic at hand is there is a fair amount of overlap in these mental models.
Now one could say that the origin of "God" is a bit murky and confusing given the different "source story" of the world and universe from different religious sects, but at the end of the day those stories were accepted as truth by those people and cultures.
Is that not similar to the creation of an egregore.
This is a very basic analysis of the terms, but there is so much more to dive into.
Please feel free to share you own thoughts...