The Apostle Paul is seeking to help this errant one in the church in Corinth to repent of his sin by advising the church to discipline such a one through separating him from the congregation of God’s people – “To deliver such an one unto Satan for the destruction of the flesh”. This phrase means to discipline through excommunication. This is what Jesus described in Matthew 18:17 as a final step of discipline to “let him be unto thee as an heathen or publican”, to treat him as an outsider of the church, to Satan’s world. He loses the encouragement and support of the brethren in the church!