The high ideals of the faith to which medieval Latin Christians were repeatedly exhorted had rendered ideas and initiatives of reform virtually coextensive with Christendom for centuries before the Protestant Reformation. The imitation of Christ through the practice of the virtues was not so much hard to understand as it was difficult to enact, whether among lay Christians, members of the secular clergy, or those men and women whose solemn vows in religious orders obliged them, at least in theory, self-consciously to pursue this virtuous imitation. “You must be perfect as your heavenly father is perfect”; “Love your enemies and pray for your persecutors”; “None of you can become my disciple if you do not give up all your possessions.” Such admonitions were all but guaranteed to produce a gap between prescription and practice. No sooner were Jesus’s commands proclaimed than Christians more often than not failed to realize them, whether they were members of the unlettered rural laity, skilled artisans and merchants in Western Europe’s burgeoning cities, parish priests scraping by on meager benefices, or powerful prelates whose positions offered constant opportunities to indulge sinful desires. No medieval Christian with the scantest grasp of the faith could have doubted that sins abounded in Christendom.