Enslavement: Jesus came to free sinners from both the punishment and the power of sin. The former was accomplished through His sacrificial death on the cross by which the people of God are declared righteous (justified) in the sight of God, and thus free from the penalty of sin.[1] The latter came through the gift of the Holy Spirit who regenerates sinners and gives them a new heart. This was the promise of the new covenant in which the Spirit would convert rebels into obedient children of God.[2] The Spirit regenerates sinners (John 3:5-8), makes them into new creatures (2 Cor. 5:14-17), circumcised of heart (Rom. 2:29) and obedient from the heart (Rom. 6:17). The Spirit frees from sin those who belong to Christ.[3] Those who are not His remain enslaved.
Reversion: Peter is deeply concerned with those who have confessed Christ reverting to their old life of sin. He likens them to unreasoning dogs and pigs. All those who fall away were never believers in the first place, because the work of the Holy Spirit is permanent. The God who begins the good work of salvation completes it to the very end (Phil. 1:6). His omnipotence renders it impossible for the children of God to ever be lost (John 6:39). True followers of Christ can never be snatched away (John 10:27-28). Children of God do not revert to their former life of sin (1 John 3:9-10). As Jesus said, “No one, after putting his hand to the plow and looking back, is fit for the kingdom of God” (Luke 9:62). Kingdom people do not return to the vomit and muck of sin.