I find religion/s fascinating. I myself went from years of being not religious, maybe a bit cultural to a degree in done aspects to someone who is a practicing muslim.
It was about 20 years ago that my fascination with religion/s started after I went to an event to refute a speaker and found him to be quite "different". Can't think of a better word here, can't say inspirational (although maybe was later as I spoke to him more).
Now this guy wasn't simply a religious guy who came to tell everyone how great his religion was, and the largely religious audience, would shout hallelujah or Allah ho Akbar etc, albeit that is what I was expecting.
He literally spent an hour telling folk that what they followed "religiously" was nonsense and in fact what they worshipped wasn't what their religion was and gave examples from the religious books and texts.
It was an eye opener and lead me to look into some of that he said and I couldn't believe how much religion being followed wasn't "authentic".
So for example I am from south Asia and the muslims there pretty much follow versions of Islam (barelwis, deobandi etc) that are from a book called baheshti zewar than Quran and Sunnah (which they all claim to be following). So much so that the arguments their speakers have on various aspects have, what I call, a false basis. And this is what often, not exclusively, causes the problem in discussions with non religious, science folk etc.
Similarly in many aspects of the other, and here for me it is mainly abrahamic, religions.