Salvation and moral training

In the course of various threads about Christians persecuted by/persecuting liberal culture, I’ve noticed a recurring theme. There seems to be the idea that behavior that some people call immoral is “contaminating” or “corrupting”; that is, the very fact that it exists is seen as an attack or affront against others who do not participate in those behaviors. People particularly resent the exposure of their children to ideas that they disapprove of, as antagonistic to their efforts to “raise their children” properly.

But I thought that the whole point was that people had free will, that each individual soul chose to be saved, or not. And that no one could be saved by their own efforts, and that it was the Holy Spirit’s job to reform people’s hearts and minds. So assuming that there’s more to it than simple hypocrisy or puritanism, just what is supposed to be the role of “moral training”?