Leviticus 21:17
Speak unto Aaron, saying, Whosoever he be of thy seed in their generations that hath any blemish, let him not approach to offer the bread of his God. Speak unto Aaron, saying, Whosoever he be of thy seed in their generations that hath any blemish, let him not approach to offer the bread of his God.
No descendant of Aaron in their generations who had any blemish was to approach to offer the bread of his God, for those who ministered in the sanctuary had to be holy, pure, and without blemish to minister before Him. This restriction was given because their work brought them into close connection with God. If one ministered in violation of this requirement, God would destroy him. The requirement reflects God's enduring and continuing holiness and purity and His exacting standard for those who minister.
The same holiness and purity are required of those who serve as ministers of Jesus. Such ministers should be pure in their words and actions. They should be marked by deep piety and deep spiritual experience. Those who meet this standard will be a blessing wherever they are.