The Morning Psalm
Bible questions

What Is Sanctification?

The lifelong process of being made holy and more like Christ.

The short answer

Sanctification is the ongoing work by which God makes believers holy — set apart and increasingly like Christ. It is God's will for us (1 Thessalonians 4:3), worked by the Spirit, and a lifelong process from glory to glory (2 Corinthians 3:18).

Set apart and being changed

To sanctify means to set apart as holy. In one sense believers are already sanctified — set apart for God in Christ. In another, they are being sanctified — progressively transformed into Christ's likeness by the Spirit over a lifetime.

For this is the will of God, even your sanctification, that ye should abstain from fornication:
1 Thessalonians 4:3, KJV

This is the will of God, even your sanctification.

But we all, with open face beholding as in a glass the glory of the Lord, are changed into the same image from glory to glory, even as by the Spirit of the LORD.
2 Corinthians 3:18, KJV

We all... are changed into the same image from glory to glory.

God's work and our effort

Sanctification is God's work in us, yet we are called to participate — pursuing holiness, putting off sin, and walking in the Spirit. It is cooperation with grace: God works in us, and so we work out what he works in.

For it is God which worketh in you both to will and to do of his good pleasure.
Philippians 2:13, KJV

It is God which worketh in you both to will and to do of his good pleasure.

Follow peace with all men, and holiness, without which no man shall see the Lord:
Hebrews 12:14, KJV

Follow peace with all men, and holiness, without which no man shall see the Lord.

Quick answers

What's the difference between justification and sanctification?
Justification is God declaring us righteous the moment we believe — a finished verdict. Sanctification is God making us actually holy over time — an ongoing process. One is our standing; the other, our growth.
Will I ever be fully sanctified?
Not in this life. Scripture promises we'll be made fully like Christ when we see him (glorification). Until then, sanctification is a lifelong journey of growing holiness.
What is my part in sanctification?
To cooperate with the Spirit — feeding on Scripture, praying, obeying, putting off sin, and pursuing holiness — while trusting that God himself is at work in you.