Compassion, or the capacity to understand, share, and care about someone else’s emotions, is often viewed as a virtue that leads to helping behavior and a harmonious society. Yet, experiencing compassion is not automatic nor easy. This project sets to deepen our understanding of the factors that promote compassion. Specifically, we suggest that religion provides the teachings and the experiences necessary for people to overcome typical hurdles to compassion. Our first aim will be to examine specific religious practices’ associations with the latest measures of compassion, including behavioral measures. We will replicate and extend the limited available evidence and provide a preliminary test of the causal influence of religious practice engagement on compassion. Our second aim will be to explain why religiosity is related to greater compassion by testing whether religion 1) provides normative, affective, and social motivations for compassion, and 2) affects perceptions of the emotional and cognitive costs of compassion. We propose a series of 9 empirical studies, accompanied by direct and conceptual replication efforts. We will produce scientific publications and conference presentations to build robust scientific knowledge with practical interest for the religious communities.