What is sanctification?

Setting Us Apart

The word sanctification means being set apart, consecrated, or made holy for a specific divine purpose. In the Old Testament, the Hebrew word qadosh describes what is set apart, distinct, or consecrated to God (Exodus 3:5; Leviticus 11:44). In the New Testament, the Greek verb hagiazō means to make holy or to set apart (John 17:17), and the noun hagiosmos is often translated as "sanctification" (Romans 6:22; 1 Thessalonians 4:3) To be sanctified is to belong to God (1 Peter 2:9). Before sanctification is about what we do, sanctification is about whose we are.

God made this clear when He called Israel to be His own people (Exodus 19:5-6).

"You are to be holy to me because I, the LORD, am holy, and I have set you apart from the nations to be mine."

-Leviticus 20:26 CSB

Holiness starts with God. He alone is holy (Isaiah 6:3), and anything else can only be holy because He claims it (1 Samuel 2:2). The tabernacle, the priests, the Sabbath, and the people of Israel were all set apart for His purpose (Exodus 29:44; Exodus 31:13). In the same way, every Christian has been claimed by God and set apart for Him (1 Corinthians 6:19-20; Titus 2:14), and belonging to Him changes the way we live our life (Romans 14:8).

Declaring Us Holy

Sanctification begins with surrender to Christ. The moment a person turns from sin and trusts in Jesus, they are set apart as God's people (Acts 26:18; Ephesians 1:13-14). This is called positional or definitive sanctification, and the New Testament always describes it in its past tense.

When the church in Corinth was addressed, they are called "those sanctified in Christ Jesus, called as saints" (1 Corinthians 1:2). "Sanctified" in its Greek is hēgiasmenois, a perfect passive participle. The Greek perfect describes a completed action whose results continue. Later, its aorist tense is used, meaning an action that is a single, completed event:

"And some of you used to be like this. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God."

-1 Corinthians 6:11 CSB

The aorist hēgiasthēte ("you were sanctified") points back to the moment of conversion. Hebrews uses the word in its perfect tense to show that this holiness rests on the finished work of Christ:

"By this will, we have been sanctified through the offering of the body of Jesus Christ once and for all."

-Hebrews 10:10 CSB

"We have been sanctified" (hēgiasmenoi esmen) is settled and permanent. God is the one who sanctifies (Exodus 31:13; 1 Thessalonians 5:23). Sanctification and justification are closely tied together, but the two are not the same. Justification settles our standing before God (Romans 8:1, 33-34). Sanctification begins with who we belong to, and then changes how we live for the rest of our lives (2 Corinthians 5:17; Titus 2:11-12).

Making Us Holy

What God declares in our moment of surrender, He works out over our lifetime (2 Peter 1:5-8). This is referred to as progressive sanctification, when the New Testament shifts to the present tense, which describes ongoing action.

Just four verses after Hebrews says we "have been sanctified," Hebrews says Christ "has perfected forever those who are sanctified" (Hebrews 10:14). The phrase in its Greek is tous hagiazomenous, a present passive participle that can be translated "those who are being sanctified." Believers are already perfected in Christ, but/and are still being made holy (Colossians 2:10; Philippians 3:12-14). 2 Corinthians uses the same present passive to describe our transformation:

"We all, with unveiled faces, are looking as in a mirror at the glory of the Lord and are being transformed into the same image from glory to glory; this is from the Lord who is the Spirit."

-2 Corinthians 3:18 CSB

"Are being transformed" (metamorphoumetha) is continuous, for as long as we live. Romans 12:12 gives us a present imperative, metamorphousthe, which can be translated "keep on being transformed by the renewing of your mind."

Sanctification is God's will for every Christian: "For this is God's will, your sanctification" (1 Thessalonians 4:3). Sanctification reaches our thoughts (Philippians 4:8), our words (Ephesians 4:29), our relationships (Colossians 3:12-14), and our bodies (1 Thessalonians 4:4). Christians will not reach perfection in this life (1 John 1:8), but over our lifetime, the fruit of the Spirit will become more evident (Galatians 5:22-23) and sin will lose its grip (Romans 6:14).

By His Spirit Through His Word

Fortunately, God did not leave us to make ourselves holy (Galatians 3:3). The Holy Spirit lives in every believer (1 Corinthians 6:19), producing His fruit in us (Galatians 5:22-23), and He gives us the power to say no to sin.

"I say, then, walk by the Spirit and you will certainly not carry out the desire of the flesh."

-Galatians 5:16 CSB

The Holy Spirit's primary guidance for us is God's Word (Ephesians 6:17; 1 Peter 2:2). On the night before Jesus's crucifixion, His prayer shows both the means and the purpose of sanctification:

"I am not praying that you take them out of the world but that you protect them from the evil one. They are not of the world, as I am not of the world. Sanctify them by the truth; your word is truth. As you sent me into the world, I also have sent them into the world. I sanctify myself for them, so that they also may be sanctified by the truth."

-John 17:15-19 CSB

Jesus did not ask the Father to remove us from the world, He asked the Father to protect us and to set us apart by the truth while we live in the world. "Sanctify" (hagiason) is an aorist imperative, a direct request for the Father to take action on us. Jesus then says, "I sanctify myself" (hagiazō, present tense), meaning Jesus was consecrating Himself to the cross on our behalf (John 10:11; Hebrews 10:5-10). Jesus's selflessness is the foundation of our holiness (Ephesians 5:25-27). The result is written in perfect participle (hōsin hēgiasmenoi), that we would stand sanctified in the truth. Sanctification is not an escape from the world. Sanctification is being set apart for God's mission in the world (John 17:18).

As we read Scripture, hear the Word of God preached, and obey God's commands, the Holy Spirit renews our minds and reshapes our desires (Romans 12:2; 2 Timothy 3:16-17). God also uses prayer (Philippians 4:6-7), baptism and the Lord's Supper (Romans 6:3-4; 1 Corinthians 11:23-26), the fellowship of the local church (Hebrews 10:24-25), and even trials (James 1:2-4; Romans 5:3-5) to make us more like Christ.

We Work For Him

If God sanctifies us, should we just stay idle and wait around for Him to do His thing? Scripture says no. Sanctification is God's work, but it is a work we take part in every day (Luke 9:23). Philippians 2 shows us that both us and God work together:

"Therefore, my dear friends, just as you have always obeyed, so now, not only in my presence but even more in my absence, work out your own salvation with fear and trembling. For it is God who is working in you both to will and to work according to his good purpose."

-Philippians 2:12-13 CSB

Both key words in this passage are in the present tense. "Work out" (katergazesthe) is a present imperative, a command to keep at it. "Is working" (energōn) is a present participle describing God's constant activity in us. We don't work for our salvation, but we keep working it out, because God never stops working in us. The New Testament is full of commands: "consider yourselves dead to sin and alive to God in Christ Jesus" (Romans 6:11), "put to death what belongs to your earthly nature" (Colossians 3:5), and pursue "holiness—without it no one will see the Lord" (Hebrews 12:14). 1 Peter grounds our call to holiness and sanctification:

"But as the one who called you is holy, you also are to be holy in all your conduct; for it is written, Be holy, because I am holy."

-1 Peter 1:15-16 CSB

Our efforts will never earn God's favor (Ephesians 2:8-10), but our efforts are our grateful response because we have God's favor.

Until We Are Like Him

Sanctification has a finish line (2 Timothy 4:7-8) that is finally being united with Christ. What God began in us at our salvation, He will complete.

"I am sure of this, that he who started a good work in you will carry it on to completion until the day of Christ Jesus."

-Philippians 1:6 CSB

"Will carry it on to completion" (epitelesei) is future tense. God Himself guarantees our outcome (Romans 8:30). This is called glorification, the moment the lifelong work of sanctification is complete.

For the Christian, our glorification comes when we are absent from the body and present with the Lord.

"In fact, we are confident, and we would prefer to be away from the body and at home with the Lord."

-2 Corinthians 5:8 CSB

When a Christian dies and goes to be with Christ (Philippians 1:21-23), the struggle with sin is over (Revelation 21:4, 27). Hebrews describes the believers already in God's presence as "the spirits of righteous people made perfect" (Hebrews 12:23). Then, when Christ returns, He will raise our bodies (1 Corinthians 15:51-53; 1 Thessalonians 4:16) and "transform the body of our humble condition into the likeness of his glorious body" (Philippians 3:21). On that final day we will be fully "conformed to the image of his Son" (Romans 8:29).

"Dear friends, we are God's children now, and what we will be has not yet been revealed. We know that when he appears, we will be like him because we will see him as he is."

-1 John 3:2 CSB

In Conclusion

Sanctification is the lifelong work of God making His people holy. The Greek tenses of the New Testament tell the whole story: we have been sanctified in Christ (1 Corinthians 6:11; Hebrews 10:10), we are being sanctified by the Spirit through the Word (2 Corinthians 3:18; Hebrews 10:14), and we will be fully sanctified when we are at home with the Lord and raised with Him (Philippians 1:6; 1 John 3:2).

Along the way we will stumble (James 3:2), but sanctification is not trying harder in our own strength (John 15:5). Sanctification is looking to Christ (Hebrews 12:1-2), depending on the Holy Spirit (Galatians 5:25), and obeying God's Word (James 1:22) until the day we see Him face to face (1 Corinthians 13:12). For the Christian, holiness is not a burden to carry but a gift faithfully given to us by God (1 John 5:3; 1 Thessalonians 5:24). So, as as we live this life, let's grow in the grace and knowledge of our Lord and Savior Jesus Christ (2 Peter 3:18).