In this article, I explore religious languages for political activism through values commonly given as reasons for becoming a unionist in Argentina. My interlocutors repeatedly emphasised their sense of vocation and service, as well as love, commitment and passion for the cause and for fellow activists or workers. Together, these related values comprise the sacred aspects of political activism, which is informed by a specific history of the blend between Peronism and Catholicism since the mid-20th Century.