Sanctification is another of those words that is not commonly used or understood in our time, except among the most Biblical of believers. We need to know what it means and experience it.
The American Tract Society dictionary gives a very accurate definition of the word sanctify:
To make holy, or to set apart for God.
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.
Exodus 19:23: And Moses said unto the LORD, The people cannot come up to mount Sinai: for thou chargedst us, saying, Set bounds about the mount, and sanctify it.
In the Old Testament, sanctification frequently denotes the ceremonial or ritual consecration of any person or thing to God: thus the Hebrews as a people were holy unto the Lord, through the covenant with its rites and atoning sacrifices.
Exodus 31:13: Speak thou also unto the children of Israel, saying, Verily my sabbaths ye shall keep: for it is a sign between me and you throughout your generations; that ye may know that I am the LORD that doth sanctify you.
The Jewish tabernacle, altar, priest, etc., were solemnly set apart for the divine service.
Leviticus 8:10: And Moses took the anointing oil, and anointed the tabernacle and all that was therein, and sanctified them. 11 And he sprinkled thereof upon the altar seven times, and anointed the altar and all his vessels, both the laver and his foot, to sanctify them. 12 And he poured of the anointing oil upon Aaron*s head, and anointed him, to sanctify him.
In the similar sense, men, sanctified themselves who made special preparation for the presence and worship of God.
Exodus 19:10: And the LORD said unto Moses, Go unto the people, and sanctify them to day and to morrow, and let them wash their clothes, 11 And be ready against the third day: for the third day the LORD will come down in the sight of all the people upon mount Sinai.
Numbers 11:18: And say thou unto the people, Sanctify yourselves against to morrow, and ye shall eat flesh: for ye have wept in the ears of the LORD, saying, Who shall give us flesh to eat? for it was well with us in Egypt: therefore the LORD will give you flesh, and ye shall eat.
A day was sanctified when set apart for fasting and prayer.
Joel 1:14: Sanctify ye a fast, call a solemn assembly, gather the elders and all the inhabitants of the land into the house of the LORD your God, and cry unto the LORD,
The Sabbath was sanctified when regarded and treated as holy unto the Lord.
Deuteronomy 5:12: Keep the sabbath day to sanctify it, as the LORD thy God hath commanded thee.
All such sanctifications were testimonials to the holiness of God, and signified men*s need of moral sanctification, or the devotion of purified and obedient souls to his love and service.