Sanctification is God’s gracious work whereby He sets believers apart for himself and progressively conforms them to the likeness of Christ. Paul addresses the church as “sanctified in Christ Jesus” (1 Corinthians 1:2), declaring a holy standing bestowed through union with the Lord; yet Scripture also calls the redeemed to grow in holiness of life. This growth does not earn acceptance with God, nor does it complete the cross’s work.
Justification is God’s once-for-all declaration that the sinner is righteous through faith, and that we have peace with God through our Lord Jesus Christ (Romans 5:1). Sanctification follows as the Spirit works in those whom God has justified, teaching them to forsake sin and walk in obedience. Both gifts belong to salvation in Christ: by the offering of his body, believers are sanctified (Hebrews 10:10), and by his continuing grace they are made fruitful in holiness. Thus the Christian rests in Christ’s finished sacrifice while, by grace, seeking to become more like him.
Sanctification is the gracious work by which God teaches His redeemed people to walk in holiness. It is not a price paid for acceptance, but the fruit of salvation already bestowed in Christ. The grace of God that bringeth salvation also instructs believers to deny ungodliness and worldly lusts, and to live soberly, righteously, and godly (Titus 2:11–14). Such growth is neither self-reliance nor passive waiting: the Holy Ghost strengthens the heart to resist sin and to obey the Lord. Therefore Scripture exhorts, “Walk in the Spirit, and ye shall not fulfill the lust of the flesh” (Galatians 5:16). When obedience is difficult, and progress seems small, the believer may rest in God’s faithfulness, not in personal merit. He who hath begun a good work will perform it until the day of Jesus Christ (Philippians 1:6). Thus grace both humbles and encourages us, calling us to pursue holiness with hope as we await the full completion of God’s saving work.