This is part 2 of a 3-part series; part 1 is found here
In 1527 Martin Luther and Ulrich Zwingli both published significant works concerning the Lord’s Supper. Both represented responses to writings from the previous year. In his Friendly Exegesis, That is, Exposition of the Matter of the Eucharist to Martin Luther Zwingli claimed that he reluctantly debated against Luther. Despite his stated irenic intentions, Zwingli incessantly pointed out the weaknesses of Luther’s teachings. He identified Luther’s teaching on the physical presence of Christ as an error very similar to Rome’s doctrine of transubstantiation. Zwingli resented Luther’s harsh verbal attacks against those who taught a symbolic understanding of the Lord’s Supper. Basing his argument on John 6, Zwingli affirmed his teaching that Christ’s words were spiritual, not carnal. For instance, he stated,
The words of Christ…we understand in this way, that to the error of the Jews through which they thought he had spoken of bodily flesh as if it ought to be eaten, Christ clearly answered that the flesh was absolutely useless to eat and not for faith either, if you considered it in a literal sense and by itself. For he says, ‘It is the Spirit makes alive.’ [Jn. 6:63] It must, therefore, be the Spirit in which one must have faith. [endnote 1]
Additionally, he rejected the idea that Christ’s human nature participated in God’s omnipresence and stated that Christ’s body was in heaven only. [endnote 2]
“How very true is the proverb that the devil is the master of a thousand arts!” With this sentence Martin Luther began his treatise, That These Words of Christ, “This is My Body,” Etc., Still Stand Firm Against the Fanatics in April 1527. Luther made it very clear that he believed the devil inspired the teachings of Zwingli and other symbolists. In this treatise he identified Zwingli, Andreas Karlstadt, and Johannes Oecolampadius by name and accused them of blasphemy for their rejection of Christ’s Words of Institution. While he feared that they would never convert, Luther hoped this refutation would win some of their disciples or strengthen the weak. He also wanted to make a public confession before the world that he had nothing to do with these fanatics. Additionally, Luther explicitly rejected any Christian unity or peace with them. He identified the heart of the controversy,
Our adversary says that mere bread and wine are present, not the body and blood of the Lord. If they believe and teach wrongly here, then they blaspheme God and are giving the lie to the Holy Spirit, betray Christ, and seduce the world. One side must be of the devil, and God’s enemy. There is no middle ground. [endnote 3]
Now Luther turned toward his opponents’ central arguments. He pointed out that God’s right hand was everywhere that God’s almighty power ruled. Christ’s incarnation united his human and divine natures in one person. Therefore, we could say that the man, Christ, is God. Christ’s human nature was no longer bound by time and space. He demonstrated this by appearing to Christians after his resurrection. Now Christ attaches his body and blood to the bread and wine in a specific manner through his Word. [endnote 4]
Luther then addressed Zwingli’s exegesis of John 6:63 which reads, “It is the Spirit who gives life; the flesh is no help at all (ESV).” Zwingli distinguished between the spirit and body of human beings. He rejected the notion that physical objects could communicate with the human soul. The Swiss Reformer asserted that the Holy Spirit nourished the spiritual nature invisibly. After the Spirit made the soul alive, Zwingli asserted that the believer partook of the bread and wine as an act of thanksgiving for an inward grace. Luther rejected this notion and emphasized the unity of the human being. For Luther, the flesh in John 6:63 was the Old Adam who lacked faith in God’s Word (Romans 8:5, 13). He also made a distinction between physical eating of Christ’s body and blood and spiritual eating through faith in God’s Word. [endnote 5]
These two works clearly set forth the controversy between Luther and his colleagues and the Swiss Reformers. Both sides understood the other to be horribly wrong. Luther, as we saw above, believed the devil inspired his opponents’ false teachings on the Eucharist. In Part III we will examine Luther’s Confession Concerning Christ’s Supper, the events of the Marburg Colloquy, and the Wittenberg Concord.
 Ulrich Zwingli, “Friendly Exegesis, That is, Exposition of the Matter of the Eucharist to Martin Luther,” Trans. H. Wayne Pipkin, Huldrych Zwingli Writings, vol. 2 (Allison Park, PA: Pickwick, 1984), 268.
 Martin Brecht, Martin Luther: Shaping the Reformation, 1521-1532, trans. James L. Schaaf (Minneapolis: Fortress, 1990), 307-309.
 Martin Luther, That These Words of Christ, “This is My Body,” Etc., Still Stand Firm Against the Fanatics, trans. Robert H. Fischer, Luther’s Works, volume 37 (Philadelphia: Muhlenberg, 1961), 13-26, (quote on p. 26); Brecht, Shaping the Reformation, 310-311.
 Martin Luther, That These Words, LW 37: 46-74; Brecht, Shaping the Reformation, 312.
 Luther, That These Words, LW 37: 78-101; David C. Steinmetz, Luther in Context (Grand Rapids, MI: Baker, 1995), 75-76.