'Set apart' in the Bible

For by one offering [i.e., the sacrifice of Himself], Christ has made perfect forever those people who are being set apart for God.

How much more severely do you think a person deserves to be punished who has trampled on the Son of God and has regarded the blood of the [New] Agreement, with which he was set apart for God, an unholy thing and has insulted the Holy Spirit, through whom God's unearned favor is shown?