Sanctification is being set apart unto God for a life of holiness.

"If you keep yourself pure, you will be a special utensil for honorable use. Your life will be clean, and you will be ready for the Master to use you for every good work."
-2 Timothy 2:21 NLT

"God’s will is for you to be holy, so stay away from all sexual sin. Then each of you will control his own body and live in holiness and honor—"
-1 Thessalonians 4:3-4 NLT