What does sanctified mean in the Bible?

To be sanctified is to be made holy and set apart as belonging to our Father. In the Old Testament, objects were sanctified for His use; people were set apart to be His. Our Father says it of His people: “Be holy to me, for I, your Father, am holy, and I have set you apart from the peoples to be mine” (Leviticus 20:26).

Holiness, then, is not first a list of rules. It is belonging. A child is set apart by being part of a family.

The Hebrew verb is qadash, to be set apart or consecrated; qadosh means holy. The Greek verb is hagiazō, and the noun hagiasmos is “sanctification.” They share a root with “saint,” one who has been set apart.

Father’s Heart Bible™ uses the plain phrase “made holy” in most places, keeping “sanctification” where Paul uses the noun: “For this is our Father’s will: your sanctification” (1 Thessalonians 4:3).

The New Testament speaks of sanctification first as something already done in Christ. “By this will, we have been made holy through the offering of Jesus Christ’s body, once for all” (Hebrews 10:10). To the Corinthians, with all their failures, Paul writes: “But you were washed, but made holy, but set right in the Lord Jesus Christ’s name and by the Spirit of our Father” (1 Corinthians 6:11).

Hebrews holds both sides together in one sentence: “For by one offering he has perfected for all time those who are being made holy” (Hebrews 10:14).

Sanctification is also a life of growing to look like our Father. “But just as the one who called you is holy, so be holy in all you do; for it is written: ‘Be holy, because I am holy’” (1 Peter 1:15–16). Paul says the fruit of belonging to Him “leads to holiness, and the end, eternal life” (Romans 6:22).

And it is His work in us: “May our Father of peace himself make you completely holy” (1 Thessalonians 5:23).

Jesus prayed for it on the night before the cross: “Make them holy by truth; your word is truth” (John 17:17). Our Father makes His children holy through His word, His Spirit, and the life of His family, as we keep turning toward Him. It is not achieved by willpower alone, and it is never earned; it is a Father shaping children who already belong to Him.