Religious history classes are quite interesting. Unfortunately, such things rarely exist before you get to college.
We have one hour a week of "Catholic religion" in high school. You can opt out if you want: you just get a free hour to read by yourself in the library (cannot leave the school, obviously). No social stigma, and no consequences in your curriculum either (the course has no tests and no grades). So what is it good for? It depends on the teacher: some use this hour trying to indoctrinate the students (haha, good luck with rebellious 15 years old), others to explain the gist of most religions, their history, differences, and similarities, or to talk about teenagers issues (drugs, sex ed, conflicts with parents and adults, etc.) I had one of the good teachers, and I really enjoyed the discussions we had (I was already a godless commie). He moved in the last year, and we got stuck with an old nun that tried to involve us in the exegesis of the finer points of the Ecclesiastes
. You can guess the results.