What Is Sanctification?
The ongoing process by which a believer is made holy and increasingly shaped into the likeness of Christ over a lifetime.
Meaning
Sanctification comes from the Greek hagiasmos, rooted in hagios, holy or set apart. Where justification describes a believer's standing before God, sanctification describes the transformation of character and conduct that follows, God's ongoing work of making a person holy in practice, not only in position.
Paul tells the Thessalonians that sanctification is God's will for them, naming specific conduct it should produce. Elsewhere he describes believers being transformed into Christ's image with ever-increasing glory, language of gradual, lifelong change rather than instant perfection. Scripture treats sanctification as both something God does and something believers actively pursue, cooperating with the Holy Spirit's work.
Traditions understand the pace and shape of this process differently. Reformed and most mainline Protestant theology describes sanctification as gradual and lifelong, never fully complete until glorification after death. Wesleyan and Holiness traditions teach that believers can experience a decisive, transformative work of grace, sometimes called entire sanctification, that deepens love and obedience in a marked way. Catholic and Orthodox theology ties sanctification closely to grace received through the sacraments, and Orthodox Christianity in particular frames the goal as theosis, a deepening union with God's own life. Despite the differences in emphasis, all traditions describe sanctification as real, God-initiated growth in holiness.
In Scripture
1 Thessalonians 4:3“For this is the will of God: your sanctification, that you abstain from sexual immorality,”
Explore more terms in the Christian glossary, see how the traditions understand it on the denominations guide, or read related verses explained.
Sanctification: Frequently Asked
What is the difference between justification and sanctification?
Justification is God's declaration that a believer is made right with him, a change in legal standing. Sanctification is the ongoing process of actually becoming holy in character and conduct that follows. Most traditions see justification as immediate and sanctification as a lifelong process.
Can a person become perfectly sanctified in this life?
Traditions disagree. Most Protestant theology holds sanctification is never complete until after death. Wesleyan and Holiness traditions teach a believer can reach a mature, decisive experience of grace deepening love and obedience, though even they generally distinguish this from sinless perfection.
Does sanctification happen automatically after conversion?
No. Scripture describes it as cooperative, God's Spirit working in a believer who also actively pursues obedience, prayer, and spiritual disciplines. It is described as a process, not a single event, unfolding gradually over the course of a Christian's life.