Prophecy, Mediation, and Power: Religion, Political Authority, and Peacebuilding in South Sudan examines the ambivalent position of faith actors between moral resistance to violence and institutional proximity to armed authority. Centering South Sudan without treating it as exceptional, the study situates the case within broader debates in political theology, religion and peacebuilding, and the sociology of religion in African politics. It develops the concept of constrained prophetic peacebuilding to explain how moral authority, institutional roles, and political pressures interact in conflict settings. Drawing on archival research in church records; interviews with church leaders, pastors, imams, and traditional spiritual practitioners; ethnographic observation of religious reconciliation practices; and comparative analysis with Mozambique, Rwanda, and Northern Ireland, the study advances three linked propositions. First, faith institutions operate within structured political constraints that shape their capacity for independent action. Second, mediation efforts—illustrated by legacies such as Wunlit—highlight both the potential and limits of religious authority in conflict resolution. Third, syncretic forms of healing and community repair play a critical role in rebuilding social cohesion beyond formal political agreements. The analysis addresses the central question of how major faith institutions in South Sudan navigate the tension between prophetic witness against violence and dependence on political authorities for security and resources. It shows that religious institutions, narratives, and practices function as political instruments as well as moral frameworks. The study concludes that peacebuilding efforts fail when they overlook the institutional constraints