My advice is that whatever you do be inviting for him to tell you what he believes and why he believes it. The more he distinguishes between what HE believes versus what he has been told, the better. But it can't be forced down his throat. The entire point of adolescence is forming the self, and a huge part of that is differentiating between what a person actually thinks about the world and his or her place in the world. It's natural for him to be at this point
When he's talking to you he's also sort of talking to himself... given the opportunity to verbalize everything, he'll be more likely to think it through.
When he's talking to you he's also sort of talking to himself... given the opportunity to verbalize everything, he'll be more likely to think it through.