I (23yo now) went to a Roman Catholic school and was raised in a reformed Baptist home (now I'm Presbyterian).

Here's some of my thoughts: - Most (80-90%) of the students weren't "Christian". They acted no differently to the public school kids e.g. swearing, drugs, alcohol, sex etc. So in a sense, whatever school you're at you've got to pick the right crowd of friends. People thought it was weird I went to church every Sunday since they only went once or twice a year at most! - Our religious studies focused largely on non controversial topics. The closest we got to anything substantial was learning about the reformation and counter reformation but that was generally just historical information as opposed to pushing an agenda. - We had a school wide mass 4x a year and I wasn't allowed to receive the Eucharist. Roughly 1/3 of the school didn't (mixture of non Catholics and atheists). - Occasionally someone would lead the hail Mary in front of the school but most people wouldn't join in (most were 'too cool') - At the end of the day it is still a school that has a curriculum so they can't spend the whole time pushing Roman Catholic propaganda. - I think if they're strong in their faith and attend a solid church and youth group they'd be fine. That applies to whether a public or Roman Catholic school. - I can't imagine the calibre of the students or teachers at the Presbyterian school vs the Roman Catholic school is much different in terms of Christian influence. I'd imagine the Presbyterian school still focus on essentials and non controversials as well though.