The central act of Christian worship is a mystery embodied in a meal. From its earliest expressions, Christianity has practiced the celebration of the Eucharist (lit. “thanksgiving,” from the Greek adjective εὐχάριστος “thankful, grateful”), later and variably also known as the Lord’s Supper, Holy Communion, Mass (Catholic), and the Divine Liturgy (Eastern Orthodoxy). The practice, which has taken innumerable liturgical forms and religious glosses in the course of Christianity’s history, at minimum both serves as the reiteration of Jesus’s final Passover meal and encapsulates a host of significant biblical and theological images and ideas, including fellowship and community, divine presence, creation, spiritual nourishment, participation, the eschatological celebration, embodiment, and the suffering and death of Jesus. The doctrine of the Lord’s Supper is a central theme in Luther’s theology and literary deposit, and it played a significant role in the development of early Protestant doctrine and practice. Worked out primarily in the course of political crises and controversies among a host of interlocutors, both Catholic and Protestant, Luther’s teaching on the Supper reflects deep-seated commitments in areas such as Christology, the relationship between theology and philosophy, and the doctrine of ministry, to name but a few, and it bears important implications for a variety of dogmatic, practical, church-political, and interdisciplinary concerns.