What Is Sanctification? Growing in Holiness by the Spirit of God
After we are justified by faith, the Christian life doesn't end — it begins. The Bible teaches that believers are to grow in holiness. This growth is called sanctification.
What Is Sanctification?
Sanctification means “to be set apart” or “made holy.” It is the process by which God, through the Holy Spirit, conforms us more and more into the image of His Son (Romans 8:29).
Unlike justification, which is a one-time declaration, sanctification is a lifelong journey. It is both positional (we are set apart in Christ) and progressive (we grow daily in holiness).
Biblical Foundations
Paul writes in 1 Thessalonians 4:3:
“For this is the will of God, your sanctification: that you abstain from sexual immorality…”
In John 17:17, Jesus prays: “Sanctify them in the truth; your word is truth.” Sanctification involves obedience, Scripture, prayer, and the work of the Spirit.
R.C. Sproul on Holiness
“Sanctification is a cooperative effort. God works in us, but we also work in response — not for salvation, but from it.”
Reformed theology teaches that while God empowers sanctification, believers actively pursue holiness as a response to grace (Philippians 2:12–13).
John Calvin: Dying to Self
John Calvin wrote:
“The death of the flesh is the life of the spirit. Therefore, we must strive for mortification daily.”
Calvin emphasizes the need to put sin to death (Colossians 3:5) and cultivate righteousness through disciplined Christian living.
John MacArthur on Real Change
“True believers will grow in holiness. Sanctification is the mark of genuine conversion.”
This transformation is not perfection, but direction — growing steadily by grace through faith.
Why Sanctification Matters
- It proves our faith is genuine (James 2:17)
- It brings joy and peace (Galatians 5:22–23)
- It glorifies God (Matthew 5:16)
- It prepares us for heaven (Hebrews 12:14)
Final Thoughts
Sanctification is God’s gracious work in us — but it is also our calling to pursue. Through daily repentance, Scripture, prayer, and reliance on the Holy Spirit, believers grow in holiness for the glory of God.