Sorry, don't have any more to add, except a side story
this reminds me of my last semester in college. I only had a few hours remaining to earn my engineering degree. One of the missing requirements was a humanities elective. I picked "World Religions", for exactly the reasons you describe about your son.
I had been raised protestant/Baptist, and really didn't know much at all about any other religion or even the denominations.... So I figured it might be a good way to learn just a bit about Catholics, Methodists, Lutherans, Jews, Buddhists, and the rest.... I was on part time status with only a couple classes left, so I figured it would be easy and eye opening.
Well let me tell you, that was by far the hardest course I took in college. I was used to some fairly rigorous classes, being an engineering major , but in engineering there is a right and wrong answer. 2+2 does not equal 3. Turned out not to be what I was looking for. It was really more about WHY people have religion, and there was a lot of stuff like...."read the following parable, and write a paragraph about what it means to you." So I would do just that, give it some serious thought, and write a paragraph. And I would get a "C", or a "D" or worse! Ugh, that was frustrating, and really brought down my GPA too! How could that be a "D", I did what he said to do?!?!?
Anyway, I hope your son finds what he's looking for.