The first problem Paul addressed in 1 Corinthians was the problem of factionalism. People had formed into groups opposed to one another, and this was tearing apart the new temple of God, which was to be built of gold, silver, and jewels, not burned up by the strife caused by wood, hay, and straw.
The second problem Paul addressed (1 Corinthians 5) is related to the first. The church had not dealt with a glaring sin in her midst. One of her members was living together with his stepmother. When we see factions in the church, we can be sure that there are sins that are not being dealt with. Here it is evident that some people were defending this man's right to commit this sin, which was forbidden by Leviticus 18:18 and Deuteronomy 22:30. Evidently one faction in the church regarded themselves as free from this "Old Testament law," failing to take account of Genesis 2:24, which states that a man is to leave his father's household when he takes a wife. Paul ordered them to excommunicate this man from the Lord's Table. He said that excommunication is for the purpose of saving the soul of the sinner as well as for cleansing the house of God. We are to hope that the pain of excommunication will bring the sinner to his senses.
Church discipline is seldom performed today. The Reformers counted solid discipline as one of the marks of a true church, along with sound preaching and the right administration of the sacraments. Today, since we want to build "large user-friendly churches," we tend to shy away from any form of church discipline. Both in the Old Testament and here in 1 Corinthians, excommunication is to be public, but while we openly boast of our church growth, we do our discipline (if we do it at all) secretly.
If we want the church to "grow" in superficial numbers, we will tone down hard preaching. Oh, an occasional pointed sermon is all right. If people don't like it, they will just tune it out for a week. Seeing someone publicly excommunicated, however, can have a "chilling effect" on superficial church members. It brings them face to face with the reality of God's judgments. But surely that is a good thing. It is the fear of God that is the beginning of wisdom.
The doctrine of justification by faith makes no sense if God is not a God of judgment. When people see God's judgments in the church, they ought to tremble and must come to grips once again with their free justification through the blood of Christ. Do you encourage your leaders to provide true biblical discipline in your church?