Jonathan Leeman writes that church discipline aims to…

1. Expose sin. Sin, like cancer, loves to hide. Discipline exposes the cancer so that it might be cut out quickly (1 Corinthians 5:2).
2. Warn. A church does not enact God’s judgment through discipline. Rather, it stages a small play that pictures the great judgment to come (1 Corinthians 5:5).
3. Save. Churches pursue discipline when they see a member taking the path toward death, and none of their pleading and arm waving causes the person to turn around. It’s the device of last resort (1 Corinthians 5:6).
4. Protect. Just as cancer spreads from one cell to another, so sin quickly spreads from one person to another (1 Corinthians 5:6).
5. Present a good witness for Jesus. Church Discipline is actually for non-Christians, because it helps to preserve the attractiveness of God’s people (1 Corinthians 5:1). Churches need to remember that we’re called to be salt and light (Matthew 5:13).