Barnes observed well, “The apostle here takes occasion, from the mention of leaven, to exhort the Corinthians to put away vice and sin. The figure is derived from the custom of the Jews in putting away leaven at the celebration of the passover. By the old leaven he means vice and sin; and also here the person who had committed the sin in their church. As the Jews, at the celebration of the passover, gave all diligence in removing leaven from their houses–searching every part of their dwellings with candles, that they might remove every particle of leavened bread from their habitations–so the apostle exhorts them to use all diligence to search out and remove all sin.”

The Apostle Paul has sensed that pride has overtaken the Corinthian Christians. He has observed that there is a false sense of spirituality built upon self-exaltation. In so doing, they have chosen not to deal with the sin that is in the camp. He warned that choosing not to see the corruption within the body will affect the wellbeing of the entire church.

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!

The Apostle Paul urged the church in Corinth to be mindful of the power that delivered them from the bondage of sin – the power of our Lord Jesus Christ. Jesus broke the stronghold of sin on the cross where He alone bore our sins. And that power is not diminished. They have been freed from the bondage of sin through the gospel. Jesus died for our sins and rose victorious over sin on the third day by His resurrection from the dead.

The Apostle Paul is deeply concerned about the toleration of sin within the church in Corinth and he is urging the leadership of the church to take the step to discipline this errant brother. He tells them his assessment of this man’s spiritual state, as though he was present with them. He needs to be disciplined so that there is a restored order in the church, an intolerance for sin to fester.

The church that does not deal with sin but allow sin to fester taints and compromises the testimony of Christ in His body. The church consists of God’s people called out from the world unto holiness with God. When the church allows the world and its filth into the church, it loses its divine power. The purpose of dealing the sin is help the errant believer come back to God. It is restorative.

The Apostle Paul pointed out there is gross immorality that is tolerated in the Corinthian Church. Fornication (sexual immorality) in the sight of God is likened to idolatry. There is a man within the congregation that has laid with his father’s wife, that is, his step-mother. And this sin has not been dealt with. The offender continues to live in sin. Moral purity, he reminded them, is what brings glory and honour to God. The exercise of great spiritual gifts without moral purity is a mockery. We serve God in holiness. This is true worship and service. Sin must be repented of and the offender disciplined.

The Apostle Paul has made plans to visit the church in Corinth. When he comes, he will not hesitate to single out and mark those who are prideful, sowing discord through inciting factions, full of empty talk but void of the spirit’s power. The Lord has granted him such spiritual wisdom to restore the peace and harmony of the church. He speaks with authority, carrying out his divine mandate. And his response toward the rebellious will be with chastisement and toward the humble and submissive, he will come in love and a spirit of gentleness. [William MacDonald]

The Apostle Paul sought to expose the empty words of these gainsayers in Corinth that sought to divide the church by creating factions. The Apostle Paul has sent Timothy to restore the peace by bringing to remembrance his mentor’s teaching for church unity and harmony. He is urging the Corinthians to submit to his leadership. He has not brought cunningly devised fables but the wisdom of God to prosper their ways. He brings them to remembrance the demonstration of God’s power in the founding of the church and the strengthening of it through the preaching and teaching of the Word with power for one and a half years whilst he dwelled with them.