If your child is partying with the "heathen" then something may have gone wrong with the inoculation process at home. I attended undergrad Christian institutions when they were more affordable in the seventies and I knew plenty of kids that went berserk and took drugs then. Remember Frank Graham? I had him in a class where he mocked the 80 year old English Ph.D. He eventually got thrown out (I saw when he was forced to leave campus) for an indiscretion on his part. The rest is history.
I just saw this the other day. I haven't read the whole discussion but I just wanted to share this. My sister went to a Christian college and found that the students there engaged in pretty much the same behaviors that students from secular, non-religious schools did. She talked about sexual activity (of course, not not witnessed personally but there was a young couple who were always together and engaged in a lot of close physical contact in public); use of profanity; students caught with use of alcohol or other drugs; and so on. Even Christians who are true believers still stumble and fall and can engage in sin. But from what my sister told me, I got the idea that some parents sent their kids to Christian schools in hopes of avoiding the wildness and partying of secular colleges; or, these were kids who had not yet made a commitment of faith to the LORD and their parents hoped the schools would serve as ministers of the gospel to them.
I went to a secular college. Honestly, after hearing of my sister's experiences, I was actually glad not to have to deal with the pressure of "you can't do this or that" at a Christian school. And I don't say this to brag but while I was there, I disciplined myself and stayed away from the party lifestyle.