Paul discusses things that can bring devastation to the church. Church is about unique relationships with others who are pursuing the Lord longing to be more like Christ. What had happened in Corinth can occur in churches in the 21st century. The Corinthian believers were allowing people who called themselves brothers in Christ, to practice sin and in some cases sin that was unnatural even to those who knew not Jesus. Those who call themselves followers of Christ have different desires then the world and should pursue them energetically. However, some in the church claim to know Christ yet are fulfilling the desires of the flesh. They are to be avoided. In Corinth sexual immorality was not unusual, but in the church an awkward scenario was occuring; a son had taken his father’s wife. So you thought your church had problems. In addition to sexual immorality there were others claiming to follow Jesus and participating in the church who were excessively greedy always wanting more unable to be satisfied and content in Jesus. There were also revilers, drunkards, and swindlers finding comfort in claiming to be a follower of Christ and hanging out with other believers. Paul adamantly charges the Corinthians with cleaning out those who claim to know Christ and continue to entertain the pleasures of the flesh like sexual immorality, greediness, drunkenness, and fraud. Paul goes to extraordinary lengths to convey that the separation is with those who claim to know Jesus yet are constantly entertaining worldly desires. He also points out specifically this has nothing to do with separating from those who do not know Jesus that are involved in worldly passions. You should associate with those in the world for them to see Christ and experience a much better life. Those in the body, the new leaven because of Christ our Passover, are to reflect sincerity and truth not malice and evil.