What is Sanctification? Revisiting the Old Testament for the Answer

Reading Time: 5 mins

The words “sanctify” and “sanctification” have deep roots in the Old Testament. There, holiness is about nearness to the presence of God. He is the holy-maker. Sanctification is his gift. The Old Testament helps us to avoid the common misunderstanding today that sanctification is all about our life of good works.

If you’re on the operating table, you don’t want your surgeon to say to a nurse, “Hand me one of them sharp thingamajigs.” You want him to have a specific name for a specific tool to perform a specific job.

Words matter. The medical field has distinctive terminology by which it carefully defines diseases, medicines, instruments, and the like.

When it comes to our bodies, we have very high expectations of our doctors. They better know what they’re talking about.

We should expect no less—indeed, far more—when it comes to pastors, priests, and teachers of the word of God. They handle the word of truth. They minister to body, soul, and mind. They better know what they’re talking about.

We don’t want to hear from them, “Now that divine power is doing some religious stuff in you.” Precision in language is necessary. We want God’s word unapologetically, lovingly, and carefully proclaimed to us.

Unfortunately, that doesn’t always happen. Consider the word “sanctify.”

Sanctification Is Not the Life of Good Works

Sanctify basically means “to make holy.” There’s a whole cluster of words in this linguistic family: holy, holiness, sanctity, sanctification.

Often, however, it seems to me that the words “sanctify” and “sanctification” are dug up from their native soil of Old and New Testaments and replanted in a strange kind of spiritualized moralism that focuses on what we do.

The result? Sanctification is understood primarily or even exclusively to mean “the life of good works.” Now good works are certainly necessary. They are central to the life of a Christian. By doing good works and living out our vocations, we serve our neighbor in love.

But “the life of good works” is not the way the Bible talks about sanctification. In fact, it’s almost completely contrary to it. Such a view makes us the active doers, instead of the faithful recipients, of sanctification—as if our actions make us holy. They do not.

Therefore, let’s quickly survey especially the Old Testament background of holiness and sanctification to do a hard reset on our understanding of what it means for God to sanctify us.

Borrowed Holiness and Spatial Sanctity

Let’s begin with a foundational truism: God alone is intrinsically, essentially, and everlastingly holy. Holiness, like divinity, is an exclusive possession of God. “You alone are holy” (Rev. 15:4). God is “holy, holy, holy” as the seraphim sing (Isa. 6:3).

Holiness is a 100% God thing and a 0% human thing. We can exercise ourselves into physical shape or study ourselves into mental shape, but we cannot sanctify ourselves into holy shape.

“Wait a minute,” you might say, “aren’t times, places, people, and things called ‘holy’ in the Bible?” Yes, of course. God says the seventh day is “holy” (Gen. 2:3). The ground around the burning bush was “holy” (Exod. 3:5). Israel was a “holy nation” (19:3). The inner room of the tabernacle was the “holy of holies” (26:34).

Well, then, if God alone is holy, how can these other things be holy, too? Because the Lord has chosen them to be so, made them to be so, declared them to be holy. He has shared his holiness with them. As John Kleinig writes in his Leviticus commentary, “[Israel] never possessed his holiness; they received it from him, just as we receive light from the sun” (407).

This, too, is crucial to realize: in the OT, holiness was spatially anchored to the presence of God in the sanctuary. The closer something or someone was to the direct presence of Yahweh, the holier it was. That’s why the inner sanctum is the Holy of Holies (or Most Holy Place) and the outer sanctum (only) the Holy Place. Likewise, even the metals used in the tabernacle and temple signified this: gold then silver then bronze, like concentric circles, were used in proportion to their nearness to the inner sanctum. The Holy of Holies was covered in gold, and, farther out, the altar of burnt offerings was made from bronze.

So, basically, the nearer to God something was, the holier it was: whether people, metals, fabrics, bread, oils, etc. Sanctity was all about spatial proximity to Yahweh.


This also explains a possible confusion. The OT occasionally talks about “consecrating ourselves” or “sanctifying ourselves.” For instance, God says, “consecrate [i.e., sanctify] yourselves” (e.g., Lev. 11:44; 20:7). The priests who approach God are to “consecrate [i.e., sanctify] themselves” (Exod. 19:22). The priests and Levites “consecrated themselves” (1 Chron. 15:14). What does this mean?

Notice, first, that immediately after God says, “Consecrate yourselves” (Lev. 20:7), he adds, “I am the Lord who sanctifies you” (v. 8). In both verses, the verb is the same, q-d-sh (קדשׁ). God is the sanctifier. The Lord is saying, “I have made and continue to make you holy; continue to be what I have made you to be.” This means, especially for the priests, do nothing to put yourself into a state of ritual impurity and, if you do, perform the rituals I have provided for your cleansing.

Self-sanctification, that is, somehow generating holiness by one’s own efforts, is an impossibility. We can no more self-sanctify than we can self-deify. When God called Israel to “be holy,” he spoke to a people he had already declared holy (Lev. 19:2; Exod. 19:6). As Kleinig says, “[God] called them to obey him because they were holy.”

Over and over in the Old Testament, therefore, God is the holy-maker. He is the sanctifier. By his word and sacred rituals of sacrifice, he bestows his holiness. He draws things and people into his presence to share his holiness with them.

Our Inner Sanctum is the Body of Jesus

The transition from the Old into the New Testament with regard to sanctification is a relatively smooth one. The big change is this: the location of holiness has changed. It is no longer the temple in Jerusalem but the flesh-and-blood temple and tabernacle, Jesus Christ (John 1:14; 2:21). He is “the Holy One of God” (John 6:69); the “holy servant” (Acts 4:30). John sees that the Lord God the Almighty and the Lamb are the temple now (Rev. 21:22).

The inner sanctum is the body of Jesus Christ. He is the source of all holiness and the agent of sanctification. From head to toe, heart to mind, skin to bones, Jesus is the Holy of Holies.

This is why Hebrews says, “we have been sanctified through the offering of the body of Jesus Christ once for all” (10:11). We are made holy by his sacrificed body. “Jesus also suffered outside the gate in order to sanctify the people through his own blood” (13:12). His blood makes us holy. Paul calls believers those “sanctified in Christ Jesus” and says that “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 Cor. 1:2; 6:11). Notice: all of these are past and completed actions. In these verses, our sanctification is a finished action, done by Jesus. We have been sanctified by the sacrifice of Jesus, made holy by his blood. It’s a done deal.

What about ongoing sanctification? Yes, the NT speaks of that also. Paul writes, “Now may the God of peace himself sanctify you completely” (1 Thess. 5:23). But who does the sanctifying? God, not the people. Hebrews says, “For by a single offering he has perfected for all time those who are being sanctified” (10:14). Note that the verb is passive: we are “being sanctified,” not sanctifying ourselves. Jesus prays to his Father, “Sanctify them in the truth; your word is truth.” (John 17:17). Again, who does the sanctifying? The Father. How? By his truth, by his word.

As in the days of Israel, so also today: sanctification is still all about spatial proximity—proximity to Jesus. The Holy Spirit, as his name suggests, makes us holy by pulling us into the holiness of Jesus. He carries us to Jesus in his church, where we can be in his presence. There, we are washed in the waters of his sanctifying baptism; hear his voice in the preaching of his sanctifying word; eat and drink his sanctifying body and blood from his altar.

By the Holy Spirit bringing us close to the holy Savior, we are sanctified, made holy, share in his sanctity.

Will good works and a holy life flow from the sanctifying work of Jesus? Yes! But sanctification is not what we do but what God does for us in Jesus Christ. We are not the active doers but the faithful recipients of the divine gift of sanctification.

Jesus makes us holy.
We are made holy.
All glory, praise, and honor be to him.