Personally, I don't really think it matters.
You aren't going to get one over on god.
If a man would murder a man to steal his watch, but only doesn't because he knows he will get caught... isn't that man still just as guilty in the eyes of god?
The would be murder is no better a man then he would be in an alternate world where he murders the man.
So to i would think, would be the case of shielding the young from "evil" literature. Does not god give man the ability to inherently know right from wrong deep inside?
It is natural to want to keep ones children from going to hell... however, you can't do it for them. You can't shield them from sin because you can't get one over on god. In fact, you might inadvertently be damning them because some people need to go through some heavy trials before they find their faith.
Sure, some people might also lose their faith during said trials... but if they would, do you think god wouldn't know that if you somehow blocked them from facing those trials?
Man's weakness, fallibility and needing help for redemption is what matters to Christians is it not?