That happens to me too, sometimes I'll get a thoughtful comment from something I wrote a year ago and I'll have no idea what they're talking about.

I find the idea of "not criticizing" anything deeply disturbing. Maybe the way to get around it would be to have a discussion on the dangers of exempting any philosophy from criticism. You'd have to trust the students to make a connection to religion on their own. If we can't discuss the shortcomings of a belief system, we submit to being controlled by those shortcomings. Interesting and complex topic!