Answer
The word translated “sanctification” in most Bibles means “separation.” It is used in the New Testament, according to Vine’s Expository Dictionary of New Testament Words, of the separation of the believer from evil, and it is the result of obedience to the Word of God. Progressive sanctification is what gradually separates the people of God from the world and makes them more and more like Jesus Christ.
Sanctification differs from justification in several ways. Justification is a one-time work of God, resulting in a declaration of “not guilty” before Him because of the work of Christ on the cross. Sanctification is a process, beginning with justification and continuing throughout life. Justification is the starting point of the line that represents one’s Christian life; sanctification is the line itself.
Sanctification is a three-stage process – past, present, and future. The first stage occurs at the beginning of our Christian lives. It is an initial moral change, a break from the power and love of sin. It is the point at which believers can count themselves “dead to sin but alive to God” (Romans 6:11). Once sanctification has begun, we are no longer under sin’s dominion (Romans 6:14). There is a reorientation of desires, and we develop a love of righteousness. Paul calls it “slavery to righteousness” (Romans 6:17-18).
The second stage of sanctification requires a lifetime to complete. As we grow in grace, we are gradually – but steadily – changing to be more like Jesus (2 Corinthians 3:18). This occurs in a process of daily spiritual renewal (Colossians 3:10). The apostle Paul himself was being sanctified even as he ministered to others. Paul claimed that he had not reached perfection, but that he “pressed on” to attain everything Christ desired for him (Philippians 3:12).
The third and final stage of sanctification occurs in the future. When believers die, their spirits go to be with Christ (2 Corinthians 5:6-8). Since nothing unclean can enter heaven (Revelation 21:27), we must be made perfect at that point. The sanctification of the whole person—body, soul, and spirit—will finally be complete when the Lord Jesus returns and we receive glorified bodies (Philippians 3:21; 1 Corinthians 15:35-49).
God’s work in sanctification involves all three members of the Trinity. God the Father is constantly at work in His children “to will and to work for His good pleasure” (Philippians 2:13). He changes our desires, making us want to please Him, and He empowers us to do so. Jesus earned our sanctification on the cross and, in essence, has become our sanctification (1 Corinthians 1:30) and the “perfecter of our faith” (Hebrews 12:2). The Holy Spirit is the primary agent of our sanctification (1 Corinthians 6:11; 2 Thessalonians 2:13; 1 Peter 1:2), and He is the one who produces in us the fruit of sanctification (Galatians 5:22-23).
Our role in sanctification is both passive and active. Passively, we are to trust God to sanctify us, presenting our bodies to God (Romans 6:13; 12:1) and yielding to the Holy Spirit. “It is God’s will that you should be sanctified” (1 Thessalonians 4:3), and God will have His way.
Actively, we are responsible to choose to do what is right. “Each of you should learn to control his own body in a way that is holy and honorable” (1 Thessalonians 4:4). This involves putting to death the “misdeeds of the body” (Romans 8:13), striving for holiness (Hebrews 12:14), fleeing immorality (1 Corinthians 6:18), cleansing ourselves from every defilement (2 Corinthians 7:1), and making every effort to supplement our faith (2 Peter 1:5-11).
Both the passive role and the active role are necessary for a healthy Christian life. To emphasize the passive role tends to lead to spiritual laziness and a neglect of spiritual discipline. The end result of this course of action is a lack of maturity. To emphasize the active role can lead to legalism, pride, and self-righteousness. The end result of this is a joyless Christian life. We are to pursue holiness, but it is God who empowers us to do so. The end result is a consistent, mature Christian life that faithfully reflects the nature of our holy God.
John makes it clear that we will never be totally free from sin in this life (1 John 1:8-10). Thankfully, the work God has begun in us He will finish (Philippians 1:6).
