Religious organizations have become crucial actors in international development. However, scholarly discussions have largely ignored the dynamics that shape their impact on the ground. This article examines these dynamics by assessing three claims about the specific developmental assets of religious organizations: (a) their credibility in the eyes of their beneficiaries; (b) their control over far-flung social networks; and (c) the idea that religious organizations pursue alternative visions of development. Drawing on existing research, we study these claims in two development sectors: healthcare and environmental sustainability. The results complicate linear narratives of the positive impact of religions on development. Dynamics internal to the religious field sometimes lead to practices that run counter to the Sustainable Development Goals, while institutional pressures in the field of international development push religious organizations to become more similar to their secular counterparts. We suggest the need for alternative frameworks that go beyond prevailing secularization and de-secularization narratives to pay attention to the institutional field dynamics that shape religious development initiatives.