What is Sanctification and Why Should I Care?

Justification vs. Sanctification

Justification is what God says about us. It changes the way He looks at us, His attitude toward us, and how He deals with us, but it does not change anything within us. God declares us no longer sinners, no longer deserving of punishment. He looks at us as sinless, innocent—the way He looks at Jesus.

Imagine standing guilty before your parents after putting a hole in the wall. One parent says, "It's okay, you may go free without punishment. I'll think of you the way I think of your obedient brother." That's justification: God treats us as He treats Jesus, declaring us righteous without changing us into His image.

Sanctification is where God makes us to be like what He says about us. God changes us to be like Jesus.

Justification rejoices our hearts—God says we are righteous with His righteousness, not our own filthy rags. We have eternal life. But salvation is more than justification. The wall-breaker goes free and gets the obedient brother's privileges, yet remains a wall-breaker at heart. We rejoice in freedom but grieve that the innocent one was punished. This stirs us: every time we sin, we ask, "Did Jesus pay for this?" We don't want to add more to His burden.

Justification declares us righteous; sanctification changes us from wall-breakers into obedient children.

Defining Sanctification

God created humanity in innocence, not perfection. Sin rotted our nature like polluted water full of disease. From this corrupted nature, we sin. Sanctification is God's process of removing the pollution and corruption from our lives—the effects of sin—and creating new, clean, better lives.

If you are being sanctified, God is changing you. He cleans out the old and creates new. This change from a polluted nature producing sin to a holy nature producing good will ultimately be visible. God makes you a new creation, and that becomes noticeable over time—whether converted at three or thirty. You are less polluted, less corrupted than before.

Three Realities from Romans 6:19-22

I am speaking in human terms because of your natural limitations. For just as you once presented your members as slaves to impurity and to lawlessness leading to more lawlessness, so now present your members as slaves to righteousness leading to sanctification. For when you were slaves of sin, you were free in regard to righteousness. But what fruit were you getting at that time from the things of which you are now ashamed? For the end of those things is death. But now that you have been set free from sin and have become slaves of God, the fruit you get leads to sanctification and its end, eternal life.

Romans 6:19-22

1. Your Sin Nature Has Changed

Once, every part of your life—body and soul—was enslaved to impurity, pollution, corruption, lawlessness leading to more lawlessness. You could do nothing sin didn't permit; you desired sin's will. Even unbelievers are restrained by God, but sin produced more sin.

Justification alone leaves us unchanged—corrupt flesh cannot inherit God's kingdom (1 Corinthians 15). God changes your sin nature to a righteous nature, recreating you to grow in holiness. Every Christian experiences this process, from the thief on the cross to the centenarian. Death is no longer wrath's sting but the final shedding of corruption.

2. Your Slave Nature Has Changed

You are still a slave, but freed from sin's clutches to slavery to God and righteousness. Sin no longer controls you; you can live free from it. No particular sin has power over you—you can cease any sin.

You are not autonomously free; you do your master's will. Now enslaved to God, who blesses His own. This slavery is true freedom to enjoy God in His goodness.

For this is the will of God, your sanctification: that you abstain from sexual immorality; that each one of you know how to control his own body in holiness and honor, not in the passion of lust like the Gentiles who do not know God, that no one transgress and wrong his brother in this matter, because the Lord is an avenger in all these things, as we told you beforehand and solemnly warned you. For God has not called us for impurity but in holiness. Therefore whoever disregards this, disregards not man but God, who gives his Holy Spirit to you.

1 Thessalonians 4:3-8

God's will: your sanctification—abstain from sexual immorality, control your body in holiness, not lust. Sanctification shows in purity, self-control, saying no to sin, desiring sin less. Lust seeks creation's pleasure over the Creator's. The sexually immoral lack control, enslaved to sin, open to all extremes.

3. Your Sanctified Nature Is Changing

"Sanctify" means to cut and separate, then to change morally toward righteousness. You join in: be diligent, serve God, seek Him in Scripture and prayer, worship. Don't be apathetic like Hebrews 5's milk-drinkers.

Sanctification brings shame over past sins—what fruit did they yield but death? Now, as slaves to God, your fruit leads to sanctification and eternal life. Reap what you sow: diligence produces holy fruit, visible in controlled speech, pure relationships. Seek those zealous for mutual sanctification in every life choice.

Why Care About Sanctification?

Blessed is the one you choose and bring near, to dwell in your courts! We shall be satisfied with the goodness of your house, the holiness of your temple!

Psalm 65:4

Strive for peace with everyone, and for the holiness without which no one will see the Lord.

Hebrews 12:14

Sanctification brings satisfaction in God's holy presence. Be holy as He is holy—it is enjoyable, the heart of true goodness, and essential for seeing God eternally.