How do we know that sanctification is necessary for Christians?

The necessity of sanctification for believers stems from the transformative work of Christ in their lives. As stated in 1 Peter 4 and supported by Romans 6, sanctification is the process whereby the believer, who is now a new creation in Christ, is called to live according to God's will. This new identity results in a divine change of heart and mind, leading believers away from their past sinful lifestyles. Scripture emphasizes that we are created for good works, ordained by God, which naturally follow from true faith. This process is not about achieving sinless perfection, but rather a continuous growth and dependence on the grace provided in Christ, demonstrating the believer's active participation in living out their new life.