This article examines how the engagement of diverse religious organisations and individuals in grassroots politics impacts the nature of politics and coalition building through a case study of an urban grassroots political coalition in Australia: the Sydney Alliance. Based on eight-months of exploratory ethnographic fieldwork in one campaign team, this article argues that whilst religious organisations bring significant symbolic and institutional resources to political coalitions, and can be flexible coalition partners, they tend to moderate both conservative and progressive political tendencies within a coalition and demand focused attention from organisers and leaders to manage the coalition dynamics. This article examines the way many religious activists understand their political action to be an inherent and necessary part of their religious practice: problematizing the characterisation common in much social science literature that religious engagement in more progressive politics primarily serves political, and not religious, ends. In doing so, it shows how political action can be directed both outward towards the work, and inward towards the ‘church’.