In the countries of the Global South, religious faith may serve as an amplifier for positive youth activism that strives for enhanced viability. This paper investigates how the positive social and environmental activism of young Muslims and Christians in Indonesia sets out to (re)shape the world according to theological precepts of divine harmony and the connectivity of all life and all humans. We make use of the work of Jeffrey, C., and J. Dyson [2022. Viable Geographies. Progress in Human Geography46 (6): 1331 1348.] on viability and ecosystems of practice in youth activism. We also employ the notion of immanence where the transcendent divine is directly experienced in the events and physical elements of the material world. Devout young activists in Indonesia make collective use of their respective theological traditions to expand their windows of perception, and to operationalise prefigurative strategies to make their world more viable. © 2024 Informa UK Limited, trading as Taylor & Francis Group.