Rates of violations against international humanitarian law (IHL) are rising worldwide. While a conceptual link between IHL norms and religion is well-established, empirical evidence regarding the effectiveness of religious appeals for IHL is lacking. This report evaluates how and under what conditions the explicit use of religious framing in appeals influences the behavior of armed actors regarding IHL compliance, and seeks to extract lessons from previous experiences of religiously framed advocacy. Focusing on Christianity, the research triangulates a qualitative content analysis (QCA) of public written appeals, semi-structured interviews, and primary and secondary sources. The findings are drawn from three primary case studies heavily impacted by armed conflict: Colombia, Nigeria, and the Philippines.