The transformation of doctrinal disagreements into sacred conflicts is one of the major challenges in Islamic theology, political theology, and the history of Islamic thought. This study examines the theological foundations and epistemological mechanisms underlying the formation of the “theology of war” in Islamic theological schools. The main question is how theological structures transform religious disagreements into sacred violence and what internal capacities exist within Islamic traditions to restrain this process. Using a descriptive-analytical method and a comparative approach, this research investigates the theological foundations of war and peace among the Kharijites, Khavarej, Mo'tazele, Asha'ere, Maturidiye va Emamiye. The findings indicate that the theology of war is not merely a consequence of legal doctrines or political conditions; rather, it emerges from a network of epistemological, anthropological, and eschatological concepts. The of truth claims, rigid identity boundaries, expansion of excommunication, and the transformation of opponents into “theological enemies” are the main stages through which disagreement develops into sacred violence. The comparative analysis shows that the essential difference among theological schools lies not in their belief in religious truth, but in their interpretation of the relationship between truth, error, and the religious other. The study concludes that confronting religious violence requires not the rejection of religion, but a critical internal reinterpretation of religious traditions based on rationality, justice, and human dignity.