I have been preaching a series of sermons on welcoming the stranger. After the resurrection Jesus appears at least twice to His disciples and they do not recognize Him until the chosen moment. Until then He is the stranger to them. Evangelism hinges on us learning to see at least the potential of the presence of Christ in the stranger. We must have an open attitude toward the stranger.
However, some strangers are stranger than others. The above paragraph does not mean that some behaviors that strangers may exhibit are acceptable behaviors. Jesus says that the world will know that we are His disciples if we love one another. Sometimes love requires establishing healthy limits.
One such limit has to do with destructive behavior in the community. Some people just get upset and don't stop to think how their gossip or back-stabbing really does not show that we love one another. Some people find themselves out of power positions they were used to for what could be good reasons, but they find it hard to let go of the prestige they enjoyed or the influence they had, or the programs they ran, and end up, consciously or unconsciously trying to undermine or sabotage the next leadership. All these must be confronted lovingly but firmly in the context of the community of faith. It must be seen as the person confronted as an opportunity to grow, to let go of pride and forgive--perhaps themselves first.
Another limit has to do with people who truly cannot control certain destructive behaviors. The mentally ill or unstable often perpetrate horrendous abuse on others with little or no awareness, or if they have awareness at the time, it quickly fades and gets explained in plausible, albeit twisted justifications. People who are manic, paranoid, or who suffer from borderline personality disorder are often very difficult to deal with in this regard. The last case is the most difficult by far.
There's an excellent book on the subject of borderline personality disorder called I Hate You, Don't Leave Me, by Kreisman and Straus. In it they suggest an approach to dealing with people with this disorder that I have found works quite well with anyone who is especially anxious. They call it "SET" and it is an anacronym for elements in a short, succinct, but clear communication with them. The letters stand for:
S: Support. Communicate support, you're in their corner, you're trying to help.
E: Empathy. You know how they feel, you can tell them how distraught they are, how excited they are, how sad, how disturbed, whatever the emotion is.
T: Truth. Tell them in clear terms what the truth of the situation is. You can describe the effects of their behavior, your expectations for their behavior, or your intended course of action, especially if it hinges on their continued bad behavior. Explanations or justifications only muddy the waters, don't bother. Short, straight shooting and to the point.
Try it some time. I have, and it works. Nasty that we have to do this in churches, but sometimes the hard line is the most loving.