Using interviews with activists and Lisa Sowle Cahill's concept of participatory discourse, this article examines how the Greater Boston Interfaith Organization (GBIO) built solidarity for the 2006 Massachusetts health care reform law. The analysis explores the morally formative connections between GBIO's activist strategies and its public liturgy for reform. The solidarity generated through this interfaith coalition's activities and religious arguments contrasts with two standard types of policy discourse, economics and liberalism. Arguments for health care reform based on economic efficiency or positive rights are hampered by the lack of solidarity in U.S. political culture. GBIO's congregation-based organizing offers a performative model of public argumentation for religious groups committed to achieving affordable, quality health care for all Americans.