ABSTRACT – Recent studies emphasize how prosocial religious beliefs promote behaviors that lead to success in intergroup competition. We build on this research by introducing the Prosocial Religion as a Resource (PRR) perspective into the field of family business. Management researchers have frequently argued that those firms that behave prosocially can acquire competitive advantage as a result. Our argument is that certain religious beliefs can induce prosocial behaviour that create competitive advantage for family firms. The causal model presented in this paper is different from but congruent with the oft-repeated claim that a generic desire to behave prosocially on the part of managers can create competitive advantage This perspective helps explain how prosocial religious beliefs can act as resources for family firms that result in competitive advantage. Our model includes the following stages: acquisition by owner-managers of prosocial religious beliefs; prosocial behavior by the owner-managers and their agents; stakeholder observation of the firm’s behavior and the improvement in firm reputation. Testable propositions are presented to explore situations where the prosocial religious beliefs of owner/managers may turn into a source of sustainable competitive advantage for family firms.