I spent many years studying history after I left. I had a lot of time on my hands.... Just study some good old ancient history.... you can track down the God concept thousands of years before christianity. You can see how that cultres basically "switched Gods around" and how belief systems developed.
Start there.... then you will see how that when christianity developed... it was basically a form of control. I wont bother telling you the details... there are many many different opinions on it.
But if you want something interesting to start with... Study the reasons why the cover of the bible says in big Gold letters.... The King James version. I mean ... everybody has their own version right? It basically came down to who had the biggest.... sword.
I myself latched on to some of the Druidic structure of belief. Check it out... pretty thought provoking.
Also, check out the history of Monks... it was basically sort of a way for some to remain silent, without offending the church. It became acceptable.
** when I say "study" I dont mean using Christian based material. You will find alot of conflicting information... Guess that is why they call it "faith". I guess you either feel a connection to the dweller of the heavens or you do not.
Overall... you will find that the history of Religion.... has very little to do with God.