What is sanctification?
Question 07015
Sanctification is what God does in the believer after conversion. If justification answers the question of the believer’s standing before God, sanctification answers the question of their state, the actual moral and spiritual condition of their inner life. The two must be carefully distinguished; confusing them is the source of considerable theological muddle and real pastoral damage.
What the Word Means
The English word “sanctification” comes from the Latin sanctificatio, and behind it stands the Greek hagiasmos, from the root hagios, meaning holy or set apart. To sanctify something is to set it apart for God’s purposes. When the word is used of the believer, it describes the process by which they are increasingly conformed to the character of God and set apart from the patterns of the old life.
There is a sense in which sanctification is already accomplished. 1 Corinthians 1:2 addresses the Corinthian believers as those “sanctified in Christ Jesus,” even though the same letter spends considerable effort addressing their ongoing sins and failures. This is positional sanctification: the believer is already “in Christ,” already set apart as belonging to God. This is not a moral description but a relational one, and it is given at the moment of conversion.
The Ongoing Work
Sanctification is also a process that unfolds over the entire lifetime of the believer. “This is the will of God, your sanctification” (1 Thessalonians 4:3). “Without holiness no one will see the Lord” (Hebrews 12:14). “Work out your own salvation with fear and trembling, for it is God who works in you” (Philippians 2:12-13). These texts together describe an ongoing transformation that is simultaneously God’s work and the believer’s genuine moral engagement.
The Holy Spirit is the agent of progressive sanctification. He produces the fruit described in Galatians 5:22-23, works the mortification of sin in the believer’s life (Romans 8:13), and progressively renews the mind (Romans 12:2). This is not an automatic process that happens regardless of the believer’s co-operation; Paul’s repeated imperatives throughout his letters make clear that the believer’s active engagement, their choices, habits, and use of the means of grace, all matter. But the power for that engagement comes from the Spirit, not from sheer human willpower.
The Goal
The goal is conformity to Christ. Romans 8:29 states that those God foreknew He also “predestined to be conformed to the image of his Son.” This conformity is not merely behavioural; it is a transformation of the whole person, the renewal of the mind, the reordering of desires, and the growth of genuine Christlike character. Paul uses the image in 2 Corinthians 3:18 of moving from one degree of glory to another as the Spirit works, a person gazing at their own face reflected in a mirror and being progressively changed by what they see.
Sanctification does not reach completion in this life. The war with the flesh continues until death or the return of Christ. Romans 7 resonates with genuine Christian experience precisely because it describes the ongoing reality of that conflict. Perfection in the sense of complete sinlessness in this life is not a biblical category. Complete transformation is the destination, but the journey there is marked by genuine conflict, genuine failure, genuine restoration, and genuine growth.
So, now what?
Sanctification is neither something that happens entirely without your involvement nor something you achieve by your own effort. The practical implication is to take seriously both the Spirit’s work and your own responsibility. Confession, Scripture, prayer, fellowship, and obedience are the means through which the Spirit advances this work. The believer who neglects them will experience genuine spiritual stagnation, while the believer who engages them will find that “he who began a good work in you will bring it to completion at the day of Jesus Christ” (Philippians 1:6).
“And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit.” 2 Corinthians 3:18
