While I haven't read it, it seems that there are a lot of very positive reviews and a lot of very negative reviews. In my experience, highly polarized opinions on books usually revolve around a belief system being put forth and/ or challenged. I can imagine myself identifying with these two reviews from Goodreads and Amazon:
"I tried to like this book, I really did. Maybe it gets better later, but I can only take so much. I tried to finish it, but the first 100+ pages simply follow the same formula over & over:
Describe part of human evolution as seen by secret societies.
Fail to explain or back up exactly what was just described.
Explain how mind-blowing what was just described is.
Point out that ancient man perceived the world differently from us and therefore was totally cool with what was just described.
Scoff at modern science for making our lives too rigid to allow us to believe what was just described.
"in summary the book
(1) cherry picks and then stitches together facts or coincidences from across history and/or mythologies/sacred texts/etc... and uses them as "proofs". As it always happens missed coincidences and things that don't fit are not treated as proofs against ;
(2) doesn't provide any justifications or links to sources that can back what it says (yes, it lists additional reads at the end but they are not linked to what's in the text... spend the next 100 years reading and cross referencing everything in this list and then we can talk...);
(3) literally from the beginning comes up with a story that could make a good fantasy or science fiction book but would be better described there and in a more believable way;
(4) in the introduction before the beginning explains that the author had extensive conversations with a person that was initiated to these mysteries but then the author decided not be initiated himself when offered the chance... which is pure genius - he got a good glimpse of all the secrets but can still write about about them without the risk of being killed by a secret society for divulging them!"