V.6 If they allowed this to go on, it would harm the whole assembly. Power to carry out discipline comes from the Lord’s presence. If we make the rules, then it would be a care of our carrying out discipline. The Word of God must be our authority. Moral sin comes from the natural mind.
V.7 “Purge,” means to clean completely, is only used twice in the New testament. Here and in 2 Timothy 2:21. In this instance they were to put away from themselves this wicked person. In 2 Timothy 2:21, the person who wanted to please the Lord was to separate from others who were not living in obedience to the Bible.
V.6-8 He explains the reason for such treatment. The Lord Jesus is in the middle of them. If they allowed a little evil, it would spread to all, and then the Lord Jesus could no longer be with them. Doctrinal evil is worse than moral evil for it attacks Christ and His work. In this chapter it is moral evil in the man, but doctrinal evil (1 Cor. 15:12) and ecclesiastical evil, verse 2, in the assembly. Putting the man away didn’t clear them. 2 Corinthians 7:11 shows that it took longer for the assembly to judge themselves than to judge the man. For their state of soul was so bad that the man had gone on in the assembly without his conscience being touched.
V.10-13 If an unsaved person was immoral, it was different from a person who was called “a believer.” From this last person they were to separate (keep away from); not even to eat an ordinary meal. But it might not be possible to keep away from immoral unbelievers, for then they would have to leave the world, because there are so many immoral people. Do you see the difference? When we are gathered around the Lord Jesus Christ to remember Him in His death, to take the bread and the wine, then there could be no known evil allowed in His Presence. It is because of His Holy Person that the care must be taken. When Christians receive any person who claims to be a believer, it is usually because they are not conscious of having the Lord’s presence in the midst.