>>>This reads to me like saying "the best way to determine if god exists is to read the hebrew bible, the koran, and the book of mormon and take the average".

That's kinda what led Aleister Crowley to create Thelema. In a very broad sense, he learned about belief systems from around the world, especially focused on "Messiah" type characters and the similarities in their experiences/stories/methods of enlightment, and then built a system that was somewhat of a fusion of all methodologies, largely as an extension of Jewish mysticism.

https://en.wikipedia.org/wiki/Thelema

Part of the problem with sticking to recently-published books is the lag time involved. Consuming a variety of current news sources can not only lead you toward a "ground truth" for that particular case, but can also frame a better understanding of other evolving situations, and arm you with a better frame of reference to not only understand those as well, but shape your actions in yet a third actively-developing scenario.