Note 6 at 1Co 5:5: Delivering this man to Satan for the destruction of his flesh was the last step in church discipline (see note 5 at Mt 18:17). There are two other men whom Paul delivered unto Satan for this purpose (1Ti 1:20). This is the negative side of Jesus' statements in Mt 18:18 and Joh 20:23.

Delivering people unto Satan does not mean we are damning them to hell, nor does it mean they are going to die physically. In this instance, we see by Paul's instructions in 2Co 2:6-7 that this man didn't die but repented and was restored back into the fellowship of the church.

This is a withdrawal of our intercession on the behalf of others and a retaining of their sins to them. This means they start reaping what they've sown because we aren't canceling Satan's activities through our prayers. This is done in the hope that these "hard knocks" will bring them to their senses. (For a more detailed explanation, see note 5 at Mt 18:17).