The Conflict over
the Lord's Supper and Baptism
Arguments over the two sacraments, baptism and the Lord's Supper, in the evangelical camp were nothing new for Luther. Infant baptism had been questioned ever since 1522, first by the Zwickau prophets and then by Karlstadt.1 In 1524–25 Anabaptism first developed as an independent movement in Zurich, and from about 1527 Luther was increasingly confronted with the Anabaptists. In general the conflict was only a limited one, for the Anabaptists were always but a small minority. In contrast, the controversy over the Lord's Supper did not remain restricted to the earlier conflict with Karlstadt,2 but encompassed large segments of the Reformation movement. Most important, however, some of the cities in southern Germany became centers of the conflict and threatened to turn away from the Lutheran Reformation. If we exclude the conflict with the Catholics, the first phase of this controversy, which lasted until 1529, persisted longer than any other conflict Luther had to endure. In fact, he remained involved with it until the end of his life. The unity of Protestantism was destroyed by this problem and could not be restored.
Once Luther had established his concept of the Lord's Supper in the second portion of Against the Heavenly Prophets at the beginning of 1525, he paused and reacted only in the next two years. The controversy about the Lord's Supper had not been initiated by him, but was forced by the agitation of the opposing side. In the sermons of 1525, he occasionally touched on the theme, attacking the "new prophets" and their disdain for the outward sign.1 Just as earlier he had considered Karlstadt to be in league with Müntzer, so he was now associating these additional opponents in the sacramentarian controversy closely with Karlstadt, and this was bound to exacerbate the conflict.
In August 1524, Luther had been informed by Franz Kolb in Wertheim that in Zurich Ulrich Zwingli was interpreting the words of institution symbolically. Thus the Karlstadtian evil was still on the loose.2 Luther's