Martin Luther had been thinking about questions concerning the Lord’s Supper for several years. Already in 1519 Karlstadt’s ideas about understanding the Words of Institution symbolically had moved Luther to preach a sermon on the subject. Several others had asked Luther about the Lord’s Supper, and Luther ha always made the point that the bread and wine truly were Christ’s body and blood. Late in 1524 Luther answered a letter from reform-minded pastors in Strasbourg, France, asking for his opinion about their idea that the bread and the wind were symbols of Christ’s body and blood. Their views were close to those of Ulrich Zwingli of Zurich, Switzerland. They followed Erasmus in their humanistic approach to interpreting Scripture; in their view any Bible passage not clear to human reason should be interpreted in a way that harmonized with reason.
In a sharply worded response, Luther said that human reason could not be allowed to change the plain meaning of Scripture. “This is My body” and “This is My blood” meant just that, even though human reason could not understand how this could be. Sola Scriptura (by scripture alone) permitted no other approach to biblical interpretation.
As Luther put it, “The Word says first of all that Christ has a body, and this I believe. Secondly, that this same body rose to heaven and sits at the right hand of God; this too I believe. It says further that this same body is in the Lord’s Supper and is given to us to eat. Likewise I believe this, for my Lord Jesus Christ can easily do what he wishes, and that he wishes to do this is attested by his own words.”
In 1529 Luther and several of his followers met with Ulrich Zwingli and his followers at Marburg. Zwingli was attempting to reform the churches in Switzerland, much as Luther was doing in Germany. Philp of Hesse, a Lutheran prince, thought it best if all reform groups would join forces. He arranged the meeting in Marburg, hoping the men could agree in all the important matters. Luther and Zwingli did agree on many points, as expressed in the Marburg Articles, but they disagreed on one very important doctrine- the Lord’s Supper. Luther insisted that Christ’s body and blood are truly preset in the Sacrament. Zwingli said that the bread and wine only stand for Christ’s body and blood and that Christ is present only in a spiritual way.
Again Luther showed that he was bound by Holy Scripture. The words “This is my body” were enough for him. He accepted them by faith, even though he could not understand how they were true. For Luther, Zwingli had committed the deadly sin of theology when he placed works above grace and reason above obedience to the Holy Scripture. Luther beautifully stated the benefits of the Sacrament in the Small Catechism, which he completed in 1529, the same year as the Marburg Colloquy. Luther and Zwingli then parted without joining forces.