The academic study of religion uses multidisciplinary, interdisciplinary, and transdisciplinary methods because of the nature of religion and the interaction between religious practice and religious studies. Prior to modernity, the study and practice of religion were integrated and separate disciplines were often assumed to study a unified subject. Thus, the terms “multidisciplinary,” “interdisciplinary,” and “transdisciplinary,” which presume strictly separated disciplines do not apply to this period. In modernity, faith-based claims in the guise of objectivity often characterized the academic study of religion, a position increasingly critiqued by academics in the late twentieth century. Yet, new modes of transdisciplinary work demonstrate how scholarship and religious practice may mutually inform each other. Ecumenical and interfaith initiatives share features with multidisciplinary, interdisciplinary, and transdisciplinary research methods and may yield helpful insights for these academic endeavors even though their commitment to an overarching worldview and life in communities set them apart.