Sanctification

The Root Idea: "Set Apart"

"Sanctification" translates two word-families in the original biblical languages — Hebrew qadash and Greek hagiazō. Both carry the same core idea: to set apart, to dedicate, to make holy.

• Qadash (קָדַשׁ, Strong's H6942) — "to be set apart, consecrated, separated from common use." The root underlies qodesh ("holiness") and qadosh ("holy").
• Hagiazō (ἁγιάζω, G37) — "to make holy, to consecrate, to set apart." The verb form of hagios ("holy").

Neither word primarily means "to be morally good" — though moral transformation often follows. The first sense is separation for a purpose. An object, a day, or a person "sanctified" is one that has been marked out from ordinary use for a specific assignment.

The Word's First Appearance

Genesis 2:3 — "And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made."

The first use of qadash in the Bible applies to a day, not a person — the seventh day of creation. To sanctify a day is to mark it off as belonging to something other than ordinary time. Throughout the Old Testament, qadash is applied to priests (Exodus 28:41), utensils (Exodus 30:29), animals (Exodus 13:2), the firstborn (Numbers 3:13), and the people of Israel (Leviticus 20:7).

The Call to Israel

Leviticus 20:7–8 — "Sanctify yourselves therefore, and be ye holy: for I [am] the LORD your God. And ye shall keep my statutes, and do them: I [am] the LORD which sanctify you."

The passage names two agents: Israel sanctifies herself ("sanctify yourselves"), and God sanctifies her ("I am the LORD which sanctify you"). This double agency — the person and God both active in the process — runs through the biblical vocabulary of sanctification.

Three New Testament Tenses

The New Testament writers use sanctification language in three grammatically distinct senses — past, present, and future:

• Past (positional) — 1 Corinthians 6:11: "But ye are washed, but ye are sanctified, but ye are justified." The Greek uses aorist passive — a completed act. Paul addresses the entire Corinthian church (including people he will rebuke in the same letter) as already sanctified.
• Present (progressive) — 2 Corinthians 7:1: "let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God." Ongoing, participatory.
• Future (final) — 1 Thessalonians 5:23: "And the very God of peace sanctify you wholly." A completed sanctification yet to come.

Sanctified by Christ's Offering

Hebrews 10:10 — "By the which will we are sanctified through the offering of the body of Jesus Christ once [for all]."

The Greek hēgiasmenoi esmen uses the perfect passive — an action completed in the past with continuing results. Hebrews develops an extended argument (chapters 9–10) that the repeated Levitical sacrifices could not finally sanctify worshippers, while Christ's single offering accomplished what the animal sacrifices pointed toward.

Sanctification and the Word

Jesus's high-priestly prayer in John 17 names Scripture as the means of ongoing sanctification:

John 17:17 — "Sanctify them through thy truth: thy word is truth."

The Greek imperative hagiason pairs sanctification directly with alētheia (truth) — and identifies that truth with the divine word (logos). The pattern is not sanctification through isolation from the world (John 17:15 explicitly rejects that) but sanctification through exposure to and assimilation of God's word.

Summary

• The root idea is separation for a purpose, not primarily moral improvement.
• Applied in the Old Testament to days, objects, priests, firstborn, and the nation of Israel.
• In the New Testament, simultaneously a past act, a present process, and a future completion.
• Accomplished by Christ's offering (Hebrews 10:10); progressively worked through truth and Spirit (John 17:17, 2 Thessalonians 2:13).