Summary

Martin Luther used the practice and notion of promise for theological and practical ends. As a theological notion, promise allowed Luther to work through important problems about God and God’s actions in Christ. Practically, Luther employed promise to understand sacraments, human action, and interpretation of the Bible.

What unites these two ends is Luther’s taking promise as a gift of God, albeit a gift difficult to categorize according to the taxonomy of gifts in cultural anthropology. God’s promise is an effective word (verbum efficax), a speech act that does what it says. In other places of Luther’s work, promise denotes an action that priests and ministers undertake in order to communicate God’s word. He used it to articulate Christ’s activity in the Eucharist. Faith can mean many things in Luther’s work, but he frequently sees it as the correlate of promise. This shows that Luther follows the practical use of promise and fidelity in the Stoic tradition in addition to his interpretation of the Bible and his theological heritage. Luther considers promise to point to something God will do in the future or that promise limits God’s power in a way that makes that promise trustworthy. When compared to a “last will and testament,” it signifies a gift to those designated as heirs. In sum, not only does promise offer practical aims for the activity of the church; it also limits and generates theological reflection on God. For Luther, “God does not deal, nor has he ever dealt, with [human beings] other than through the word of promise” (De captivitae babylonica (1520) WA 6:516, 30–33; LW 36:42, translation modified).