One of the most amazing things to me about the Bible is all of the fulfilled prophecies, especially the ones that weren't self-fulfilling. Here are Jesus enemies actually fulfilling prophecy. They have every reason not too, and they do it, probably because they were unaware. Sure Jesus claimed to be the Messiah and even had evidence to prove that he was, but they refused to believe. It's almost like they didn't want to believe.
We like to think that we can create the perfect program that will minister to everybody. But it can't be done. It's still up to the individual to determine how they will respond. Even people that are heavily committed to your program can still walk away unchanged. The point is to mitigate the percentage that do that by creating a relevant, inspiring ministry.