The belief that the Mother of Jesus was never stained with any sin, original or personal, and was also free from all unruly desires or concupiscence. By itself, deliverance from original sin does not mean liberation from the defects that are the result of sin. Mary, like Christ, was not exempt from those limitations which imply no moral imperfection. She lived a normal human life, had to labor, and was subject to pain and fatigue. But concupiscence implies moral blemish because it may lead to sin by exciting the passions to act against the law of God, even when, through lack of consent, a person does not formally do wrong.
Closely tied in with her integrity or absence of concupiscence was Mary's immunity from every personal sin during life. Her sinlessness may be deduced from the Gospel title "full of grace," since moral guilt is irreconcilable with fullness of God's friendship. St. Augustine held that every personal sin must be excluded from the Blessed Virgin "because of the honor of God."