Unity isn't always to be desired. Division isn't always to be avoided. What's more important than unity and division is the purpose of the unity or division. In 1 Corinthians 5 we learn that the purity of the church is the priority of God's church. To that end, there comes a time where the church must remove certain members to maintain this purity. Far from being judgmental and condemning to the straying member, when church discipline is done rightly it provides (1) hope for the straying and (2) joy for those that remain. God shows His incredible grace and wisdom in the way that He instructs us as a church to deal with sin in the life of the church. He doesn't want us to be ashamed, but assured of our salvation. To this end, church discipline is a gracious gift from a loving Father.