Religion has resurged as a powerful social and political force worldwide, yet conventional international relations frameworks within the political science discipline offer limited insight into how religious ideas, actors, and institutions shape global dynamics. To bridge this gap, this chapter begins with a conceptual examination, defining religion broadly across diverse faiths. It then reviews relevant literature, highlighting how religious motivations impact not only armed conflicts but also peacebuilding efforts. The analysis recognizes that while religion is seldom the sole cause of conflict, it plays a complex role, providing tools, challenges, and opportunities for conflict resolution and peace. The chapter concludes by advocating for continued research to clarify these dynamics, emphasizing that understanding religion's multifaceted role in IR is crucial for policymakers aiming to address the nuanced ways in which religious values influence global conflict.