Marriage and the regulation of sexual intercourse are primary concerns in all of the early penitentials. Each of these manuals represents an individual contribution towards a broader effort by religious authorities to promote the matrimonial ideals of the Church according to the parameters established by Leo the Great in the fifth century. Although the pope's directives did not make marriage a sacrament, they did attach a measure of sanctity to particular unions and established a precedent of authority in defining which were legitimate, thus linking the social and spiritual. The penitentials, as religious texts, collaborated in the effort to realize that authority in different ways. As prescriptive texts, they also reveal the tenacity, real or perceived, of customary conjugal patterns that deviated from the ideals they sought to promote.

In confronting these challenges, the penitentials laid out regulations and penances that cumulatively circumscribed sexual intercourse as a concession, permitted for certain people, at certain times, for a specific purpose, and within a particular type of union: consensual, nominally permanent, and legitimized by the approval of the Church. As a result, they give a good deal of space to discussions of sexual behaviours that fell within the broad category of adultery as sexual relations involving partners outside of marriage, again according to the ideals they sought to advance. They did not, however, present a unified, oppositional stance to customary conjugal patterns. Nor did they insist on ascetic sexual renunciation for all. Rather, they focused their attention on issues within the sphere of discipline they advocated, according to the potentialities anticipated in a given time and place, while recognising, within bounds, the reality of human sexuality.

Overwhelmingly, studies of these handbooks focus a great deal of attention on the ways they discuss sexual transgressions. This makes sense, given the amount of space the manuals devote to such concerns and their apparent candour in discussing what so many early medieval texts do not. Pierre Payer particularly advanced the value of the penitentials for the history of medieval sexuality, followed by many others, including notable studies by James Brundage and Vern Bullough. Often, however, analyses of the penitentials as exemplars of medieval social mores involve assumptions of equivalence between medieval and modern understandings of sex and sexuality, or equally misleading generalizations about the relative silence many of these manuals have about female sexuality.