How does the Spirit sanctify us?
Question 04021
Sanctification is not simply a matter of moral improvement or religious discipline. It is the Spirit’s work in the believer, transforming what we are from the inside out rather than merely adjusting behaviour on the surface. Understanding how the Spirit actually does this changes the way a Christian approaches the whole project of growing in holiness.
Two Senses of the Same Word
Scripture uses “sanctification” in two distinct senses that must be kept separate if the believer is to make sense of their own experience. Positional sanctification is complete, permanent, and received entirely as a gift at the moment of conversion. Paul addresses the Corinthians as “those sanctified in Christ Jesus” (1 Corinthians 1:2) despite the considerable moral chaos evident in that congregation. This is not flattery. It reflects the reality that in Christ, the believer has been set apart, holy before God by virtue of their union with His Son. This standing cannot be improved upon, because it rests entirely on Christ’s work.
Progressive sanctification is the ongoing process by which the Spirit makes the believer’s actual life increasingly consistent with that position. Peter’s command, “as he who called you is holy, you also be holy in all your conduct” (1 Peter 1:15), is addressed to those who are already positionally sanctified. The call is not to become something they are not, but to live out what they already are. The Spirit is the divine agent making that possible.
The Spirit’s Instruments
The Spirit does not sanctify in a vacuum. He works through means, and Scripture is clear about what those means are. The Word of God is primary: Jesus prayed, “Sanctify them in the truth; your word is truth” (John 17:17). The Spirit uses Scripture to expose sin, reshape thinking, and align the believer’s desires more closely with God’s. This is why Paul instructs, “be transformed by the renewal of your mind” (Romans 12:2). The transformation is real, but it proceeds through the Spirit’s illumination of the Word, not apart from it.
The Spirit also works through the mortification of sinful habits and desires. Paul writes, “if by the Spirit you put to death the deeds of the body, you will live” (Romans 8:13). The preposition matters enormously. The putting to death is the believer’s action, but it is accomplished by the Spirit. Human effort is involved, but it is Spirit-enabled effort. This is why the New Testament never encourages passivity (“let go and let God” has no biblical warrant) nor does it commend willpower alone. The Spirit energises the believer’s own struggle against sin.
The Renewal of the Inner Person
Paul’s description in 2 Corinthians 3:18 captures the direction of the Spirit’s work: “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.” The transformation is progressive (“from one degree of glory to another”), it moves toward a specific goal (conformity to Christ), and its source is the Spirit. Beholding the Lord, through the Word and through prayer, is the means. The Spirit does the transforming.
This is why sustained engagement with Scripture and prayer are not optional extras for the keen Christian. They are the conditions under which the Spirit does His characteristic work. A believer who neglects the Word is not simply missing information; they are removing themselves from the primary instrument through which the Spirit reshapes the inner person.
The Spirit and the Flesh
Sanctification is not simply addition. The Spirit does not add holiness to an unchanged sinful nature. Paul describes an ongoing conflict: “the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other” (Galatians 5:17). The Christian life involves a genuine contest, and the Spirit’s role is not to end that contest prematurely but to give the believer the resources to win it, day by day. This is why progress in sanctification is often more visible in retrospect than it is in the moment.
So, now what?
The practical implication is that the believer does not have to choose between effort and dependence. The Spirit works through the believer’s active cooperation: reading the Word with openness, confessing sin promptly, yielding to the Spirit’s promptings rather than suppressing them, and engaging seriously with the ongoing battle against the flesh. None of this earns standing before God. All of it matters for growth. The Spirit is not waiting to work until the believer is perfect enough; He is at work in the imperfect believer precisely to bring them closer to what they will one day fully be.
“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