Wittenberg Sermon, 1540

In a sermon preached in Wittenberg on this day in 1540, Martin Luther testified, “Faith is the ‘yes’ of the heart, a conviction on which one stakes one’s life.” Spoken late in his ministry, the line gathered up decades of teaching: faith is not a mood, a tradition, or a cautious opinion, but a settled reliance upon God’s promise in Christ.

Wittenberg—home to the University of Wittenberg and the church doors that first carried Luther’s call for reform—served as a fitting setting. Here, believers were urged to look beyond mere religious habit and to cling to the gospel when fear rises and circumstances threaten. Scripture echoes this steadiness: “Now faith is the assurance of what we hope for and the certainty of what we do not see” (Hebrews 11:1).

Martin Luther (1483–1546)

Luther’s words in 1540 were forged through conflict, opposition, and personal cost. After the Diet of Worms (1521), where he refused to recant teachings he believed bound to Scripture, he lived under threat and experienced exile at the Wartburg Castle. There he translated the New Testament into German, a labor of courage and service that strengthened the church by placing God’s Word in the hands of ordinary people.

His heroism was not the bravado of self-confidence, but the endurance of a conscience captive to God’s truth. This kind of faith produces obedience that stands firm under pressure and humility that refuses to boast in works. “The righteous will live by faith” (Romans 1:17) was not a slogan to him, but a lifeline.

Legacy for the Church

Luther’s 1540 sermon continues to call believers to wholehearted trust—faith that says “yes” to Christ when doubts whisper and trials tighten their grip. Such confidence honors God, not because it is perfect, but because it rests in a perfect Savior. It also strengthens Christian virtues: courage to confess, patience to endure, and love to serve neighbors without seeking approval.

His testimony directs the church to stake life—not on shifting feelings—but on God’s sure promise in the crucified and risen Lord.