From what I have learned about “his-story” and the origin of “religion”, is that there can be no certainty since the only “truth” is that which is written down and passed down by the winners of Wars. The conquering societies create their version of “his-story” and destroy all others. There is though this common thread between all “religions” that are accepted in each and that “thread” is the only “truth” that is “true” because if it is evident and prevails in all of them then that is what will continue to be repeated in anything new because it has always existed in everything before. Everything else is just bloatware and usually only a matter of prejudicial preferences from the fears of those who seek to be in control of the uncontrollable. Hope this helps :D