Leviticus 21:6
They shall be holy unto their God, and not profane the name of their God: for the offerings of the LORD made by fire, and the bread of their God, they do offer: therefore they shall be holy. They shall be holy unto their God, and not profane the name of their God: for the offerings of the LORD made by fire, and the bread of their God, they do offer: therefore they shall be holy.
Those who minister in the sanctuary are required to be holy, pure, and without blemish, because their work brings them into close connection with God. Their holiness is required in view of presenting the Lord's offerings made by fire, the bread of God that belongs to Him. Failure to meet this requirement of holiness brings judgment. The requirement reflects that God's holiness, particularity, and standards do not change. Ministers of Jesus, who care for the flock and handle God's words, must likewise be pure in speech and conduct and deeply devoted and pious toward God.