The basic distinction: justification vs. sanctification
Christian theology distinguishes sharply between two aspects of what God does for sinners:
- Justification — the legal declaration that a sinner is righteous before God, based on the imputation of Christ's righteousness received through faith. This happens at the moment of conversion and is complete — God's verdict does not change. A justified person is not made righteous; they are declared righteous.
- Sanctification — the actual, progressive transformation of the believer's character, desires, and behavior toward genuine righteousness. This is a process that begins at conversion and continues throughout life. A sanctified person is not just declared righteous; they are being made righteous.
The Protestant Reformation was largely fought over justification — whether it is by faith alone or by faith and works. But sanctification is equally important for understanding what the Christian life is supposed to look like.
Three aspects of sanctification
Definitive sanctification
At the moment of conversion and union with Christ, something decisive happens: the believer is set apart (the literal meaning of "sanctify" — to make holy or set apart) as belonging to God. Paul addresses his letters "to the saints in Corinth" — not because the Corinthians are morally perfect, but because they have been definitively set apart. This is the once-for-all, past-tense aspect of sanctification.
Romans 6:1–14 is the key text: "We died to sin — how can we live in it any longer?" Paul's argument is not "try harder to stop sinning" but "you have already died to sin; now live accordingly." The indicative (what is true) grounds the imperative (what to do).
Progressive sanctification
The ongoing, lifelong process of genuine moral and spiritual transformation — becoming more like Christ in character and conduct. This is the aspect of sanctification most commonly discussed:
- It is the work of the Holy Spirit in the believer — God working in us to will and to do his good pleasure (Philippians 2:13)
- It involves human effort and cooperation — Paul also says "work out your salvation with fear and trembling" (Philippians 2:12) and uses athletic imagery (running, fighting, disciplining the body)
- It is uneven, non-linear, and sometimes imperceptible — real growth is happening even when it cannot be directly felt or measured
- It involves the ordinary means of grace — Scripture reading, prayer, fellowship, the Lord's Supper, service — through which God works to transform his people
- It is never complete in this life — the most mature Christian continues to struggle with sin until death
Final sanctification (glorification)
At death (or the return of Christ), the believer will be finally and completely freed from the presence and power of sin — made perfectly holy, fully conformed to the image of Christ. This is not just the forgiveness of sins but the actual transformation that progressive sanctification was moving toward. 1 John 3:2: "When he appears, we shall be like him."
Denominational differences on sanctification
Reformed / Calvinist
Sanctification is entirely the work of God, worked out through means (Scripture, prayer, sacraments, community) and involving genuine human effort — but that effort is itself God's gift. Sanctification is gradual, lifelong, and never complete before death. There is no "second blessing" or crisis experience that brings the believer to a higher level; growth is ordinary and slow.
Wesleyan / Methodist / Nazarene
John Wesley taught "entire sanctification" — a second, definite work of grace, subsequent to justification, in which the Holy Spirit purifies the believer's heart from the root principle of sin (inbred sin). The sanctified believer is not perfect in knowledge or free from mistakes, but the orientation of the will toward sin is healed. This doctrine sets Wesleyan and Holiness traditions apart from Reformed Christianity.
Catholic
Sanctification (theosis — participation in the divine nature — in Orthodox language; divinization in Catholic) is understood as the goal of the whole Christian life. The sacraments are the primary channels through which grace flows to enable sanctification. Purgatory is understood as the final sanctification for those who die before the process is complete.
Pentecostal / Charismatic
The Holy Spirit's role in sanctification is emphasized strongly. Baptism of the Holy Spirit (with or without tongues as evidence, depending on the tradition) is understood as empowering believers for holy living and effective ministry. The Spirit's gifts and fruit (Galatians 5:22–23) are both aspects of sanctified life.
Frequently asked questions
If sanctification is God's work, why do I need to try?
This question cuts to the heart of the tension Paul holds in Philippians 2:12–13 — "work out your salvation... for it is God who works in you." The Reformed answer is that human effort and God's work are not competing; God's work includes and operates through human effort. The fact that God is working does not make human effort unnecessary — it makes human effort possible and meaningful. The fuel for sanctifying effort is not guilt or law but the Gospel: gratitude for grace, not striving to earn it.
Can I lose my sanctification?
You can sin grievously, regress in growth, and go through long periods of stagnation — all of which are part of the normal (if painful) experience of Christian life. Whether you can lose your salvation entirely is a separate question on which Calvinist and Arminian traditions disagree. See our guide on predestination.