An old Zen story ...
There was once a very popular Zen master. Due to his virtue & his skillful delivering of sermons, the lecture hall was always full.
There happened to be a thief among his congregation. This man would steal every once in while a during service. Every time he was caught, the master would counsel him and then ask the congregation to forgive him.
This went on for a while until the congregation got sick of this thief. On one particular day, a head monk representing the congregation issued an ultimatum to the master. Either he expels the thief or the entire congregation would leave.
The master answered, "Then all of you, please leave". He then explained to the shocked crowd, "All of you know that stealing is wrong, but he doesn't. If I don't teach him, who will? This man needs my guidance and my love more than any one of you. If I have to lose all of you to keep him, let this be the case".
The thief was so touched by this that he started to cry. From that day on, he never stole again.