Why was the Eucharist and its practice responsible for the near breakdown of the reformation? Cameron says that this issue involved more mutual misunderstandings, clashes of character and fixed exegesis of scripture than almost any other issue of the reformation. Before we concentrate on the differences let us just mention some of the agreements over the eucharist. Basically all agreed that there should be no catholic mass. They all rejected its claims to be a sacrifice and a good work. Also the adoration of the elements was also condemned by the reformers. The problem that arose revolved around the sense (if any) in which Christ’s body was present in the Eucharist, and the significance surrounding the words “This is my body”. These issues caused Luther anxiety. He resolved it by concluding that real bread and wine remained on the alter in which Christ’s real flesh and real blood are present. In other words, for Luther, two realities existed at the same time. Luther illustrated this by using a red hot iron. Both iron and fire are present at the same time, thus with the Eucharist, the bread and body, the wine and blood are together. Beyond this Luther was unwilling to speculate or develop his theology claiming that we should not dabble in too much philosophy.
Huldrych Zwingli developed a distinctly new view on the Eucharist, which could not be further from Luther. The words “this is my body” must be figurative, just as “I am the vine” was a figure of speech. The sacrament is only a sign and the sign and the thing signified cannot be the same . The Eucharist enables you to feed spiritually from Christ by faith. The wine and the bread are merely symbolic and so Christ is present merely in a spiritual sense, through the faith of the believer.
Thus were the battle lines drawn between Luther and Zwingli and their adherents.
 Cameron pg 163
 W P Stephens The Theology of Huldrych Zwingli (OUP 1986) pg236