Brethren, even if a man is caught in any trespass, you who are spiritual, restore such a one in a spirit of gentleness
Are there any occasions when Christians should confront each other on matters of behavior? Yes. We are required by God to confront and restore those who have clearly violated the boundaries of Scripture (Matthew 18:15-16). But let me alert you to an important distinction in this area: Discipline is an issue of confronting observed behavior--that which you have personally witnessed (Galatians 6:1); judgment is an issue of character. We are instructed to confront others concerning sins we have observed, but we are not allowed to judge their character (Matthew 7:1; Romans 14:13). Disciplining is our responsibility; judging character is God's responsibility.
For example, imagine that you just caught your child telling a lie. "You're a liar," you say to him. That's judgment, an attack on his character. But if you say, "Son, you just told a lie," that's discipline. You're holding him accountable based on an observed behavior.
Or let's say that a Christian friend admits to you that he cheated on his income tax return. If you confront him as a thief, you are judging his character and that's not your responsibility. You can only confront him on the basis of what you see: "By cheating on your taxes, you are stealing from the government and that's wrong."
Much of what we call discipline is nothing less than character assassination. We say to our disobedient child: "You're a bad boy." We say to a failing Christian brother or sister: "You're not a good Christian." Such statements don't correct or edify; they tear down character and convey disapproval for the person as well as his problem. Your child is not a liar; he's a child of God who has told a lie. Your Christian friend is not a thief; he's a child of God who has taken something which doesn't belong to him. We must hold people accountable for their behavior, but we are never allowed to denigrate their character.
Prayer: Forgive me, Father, for judging others. Enable me to discipline in love those I care about and for whom I am responsible.