They think that pedophilia is something you do rather than something you are. I've had people who learned about my inclinations tell me "don't ever become a pedophile", not realizing that it was my natural orientation. They think pedophile is synonymous with child molester/rapist/abuser. The first step is making them understand that this is our natural orientation regardless of whether we ever act on it. Second step is getting them to realize that not all sex acts with children/adolescents are the same, and that there are age appropriate ways to sexually interact with them in a way that doesn't hurt them and which they can consent to. But first things first...