During Europe in the Middle Ages, how religious was the "average Joe"? Looking at the large scale politics of the time it seems religion was a major part of the elites' lives, with treaties with the papacy, crusades, excommunications of kings etc. But to my knowledge all this is geared around the upper classes - knights, lords, barons and kings, and was to a large extent realpolitik. Do we have any evidence that peasants were either insincere in their profession of belief (a profession which was compulsory, I'm pretty sure), or at least any lack of interest or ambivalence in organized religion?