The greater the sinner, the greater the saint
Possible interpretation: 1) If a bad person can become good, a very bad person can become very good. Someone with great energy for doing bad, may, when he chooses, apply it equally to doing good. 2) Converts are the most zealous. In a day-to-day sense, for example, someone who has given up smoking may preach more about the virtues of not smoking than someone who never smoked.Note: sinner (noun) = a person who breaks the law of God | saint (noun) = a person considered to be holy and virtuous (especially by the Church)
Origin: This paradoxical and controversial saying dates back many years and seems to have no theological grounding. It may have been invented to justify the actions of a historical personage (to wit Robert the First Duke of Normandy).