The development of children’s religious concepts is influenced by socio-cultural factors, such as the beliefs, doctrines, and rituals of their religion. A mechanism by which socio-cultural factors influence concept development is through the internalization of cultural concepts. Children’s ability to understand intention allows internalization to happen. The present study interviewed children between the ages of 4- and 7-years-old to assess their understanding of intention in the context of the ritual of baptism as well as their concepts of God and supernatural causality. Children judged the efficacy of four variations of a prototypic baptism, which varied in the practitioner’s intention and performance. Children’s efficacy judgments held together among two dimensions: intentional and accidental acts. Children’s efficacy judgments of intentionally performed religious behavior was related to their concept of God’s knowledge. Children’s efficacy judgments of accidentally performed religious behavior was related to their concept of God’s properties and natural explanations of baptism. These findings are discussed in terms of why intention understanding along these two dimensions influences the internalization of religious concepts differently.