1 Corinthians 5:5
To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus. To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
The instruction belongs to the direction given to the Corinthian church to confront and remove those who were disgracing it by sexual sin. The wrongdoing was exposed by letter so that repentance and corrective action could take place before Paul's visit, and the discipline was intended both to deal with the evil and to give the sinner opportunity to repent. To be delivered to Satan means that one separated from Christ by sin stands in peril of being given over to Satan, whose power God may permit to act. Those who remain faithful to God and cling to Jesus by living faith are guarded by heavenly angels from Satan's destructive power.
Applied to sexual sin, one who knowingly breaks the seventh commandment is to be suspended from church fellowship and from the privileges of the house of God rather than retained on a confession of sorrow alone. The sin is knowing and grievous, and to treat it lightly brings God's displeasure and harms the church, especially its young people. Therefore the soul must be kept free from defilement, centered on God's glory, and sober and watchful in prayer.