Okay, let's look at this a different way. I didn't say to put the fox in charge of the henhouse. And knowingly doing that would be stupid. If someone (even a wolf) wants to mingle with the congregation, and the shepherds there have taught their flock well, why are you so afraid? Has God given us a spirit of fear?
I was once a wolf. Yet now am not. Is that because people shunned me? Or was it the other way around? I am glad that the people who were entrusted with God's spirit, reached out to me. I am glad that I wasn't shunned, but allowed to come into the fold. I have been beaten with the rules. It truly didn't help or change me.
We are to reach out even to those who mistreat us.
We are to repay harm with help.
If we are mistreated we are supposed to emulate our Lord.
What was it He did on the cross?
Oh yeah, He cursed them all for... No, wait.
He prayed for those who despised and mistreated Him.
He wished for their misplaced self-righteousnous to turn into something else.
It doesn't mean we don't punish law-breakers. It does mean we are still to offer help. Sometimes that help comes through incarceration and treatment. That's what the law is for. And in this fallen world, it will still be that way. But Jesus came to serve. Even His enemies. Especially His enemies.
Of course, if you know better and are more right in your self than Jesus, you can condemn them. After all 'that sin' is far worse than any you've ever done, right?