There is in all of us, even the genuine follower of Jesus, a Pharisee that continually tries to get out and take over. Pharisees were those individuals who could take the clearest and most beautiful parts of the Gospel and turn them into lifeless religious behaviors. While looking pious and holy, all the while the Pharisee is the person who totally misses what God is offering.
When I read 1 Corinthians 5:9-11, I recognize how modern day Christians (me included) quickly play the part of a Pharisee when applying this verse. It says: