During the 1520-1540s, the introduction of the Reformation in Switzerland went hand in hand with multiple quarrels about tithes, right of patronage, the attribution of funds to clergymen, or the use or reparation of religious buildings. Through these conflicts, secular authorities and communities were not only trying to favour or prevent the progress of these new ideas, but also to promote their own individual interests. They combined the use of the right of collation, patronage, alliance treatises, and national peace as judiciary tools in order to ensure, throughout these means, their own salvation and that of their allies, but also to obtain concessions about older quarrels, pertaining to more worldly matters. This article shows that Reformation was not only a matter of conviction and personal faith, but that it was also the occasion of judicial and economic dealings that contributed to redraw the confessional map of the Old Swiss Confederation. The valley of Moutier offers a good example of these logics: the valley was disturbed by a discord that lasted several years, during which two cantons, with opposite confessions, became allies in order to demand to their inhabitants to pay the tithe. In this situation, the Reformation appears thus as a complex and fragile moment, where procedures and temporal interests were as crucial as new religious ideas.