what's your current major? why change?
Religious studies is interesting. I wouldn't choose a major based on what's simply fascinating to you. I'm the kind of person with a plan A, B, and maybe C...so if I didn't do med school I wanted my major to be semi-useful in the workforce. Maybe a religious studies major is fine, but it seems to me, other than medicine, you'd either have to go on to graduate school or go to seminary.
What does one get out of any education in general? The most important thing for your education, to me, is learning how to think. Pure and simple. If you know how to think (i guess that's sufficiently ambiguous), you can tackle most things. I also liked my liberal arts undergrad, because I was able to challenge myself in many fields that I wouldn't have otherwise (classics, literature, philosophy, religion, politics, and economics). To me, it was both fascinating and useful.
Basically, I wouldn't choose a major primarily because it is fascinating. It's a plus, but to me its not the only reason. I tend to steer people away from majors a la Super Sad True Love Story's "major in Images and a minor in assertiveness"...a real life equivalent, no offense, would be business communications (to me, at least).
I hope that was mildly helpful.