Founded over a century ago, the Mennonite Central Committee (MCC) is regarded as one of the most important institutional carriers of Canadian and American Mennonite identity. Generations of Mennonites and others have served with the organization, carrying out development, disaster relief, and peacebuilding work in over fifty countries globally. The Service of Faith offers an ethnography of MCC’s Christian development work in Indonesia, exploring the challenges, conundrums, theologies, and ethical commitments that shape Mennonite service. The success of religious-based development work depends on effectively bridging very different cultural and religious worlds. Braiding together extensive ethnographic and archival research, Philip Fountain analyzes MCC’s practices of cultural translation in the Indonesian context. While the particularities of Mennonite religious values are deeply influential for MCC’s work, in practice its humanitarian project involves collaboration with a range of actors who come from widely varied religious positions. In taking a nuanced, case-specific approach to understanding how faith shapes moral projects, Fountain challenges mainstream claims to secular neutrality and the tendency to dismiss or disapprove of religious motivations in development work. Exploring the diverse ways in which Mennonite convictions permeate MCC’s work in Indonesia, The Service of Faith confronts the question of whether religion has a legitimate place in international development work.