Not content with maledictions, Luther then turns himself to prophecy; he announces that his doctrine, which proceeds from heaven, will gain, one by one, all the kingdoms of the world. He says of Zwingli's explanation of the eucharist, "I am not afraid of this fanatical interpretation lasting long." On the other hand Zwingli predicted that the Swiss creed would be handed down from generation to generation, crossing the Elbe and the Rhine. Prophet against prophet, if success be the test of truth, Luther will inevitably have to yield in this point.
The Reformation, which at first was entirely a religious phenomenon, soon assumed a political character; it could not fail to do so. When people began to exclaim, like Luther, on the house-tops: "The Emperor Charles V ought not to be supported longer; let him and the Pope be knocked on the head;" that "he is an excited madman, a bloodhound, who must be killed with pikes and clubs," how could civil society continue subject to authority? It was natural that the monk's virulent writings against the bishops' spiritual power should be reduced by the subjects of the ecclesiastical superiors into a political theory. When he proclaimed that the yoke of priests and monks must be shaken off, we might expect that this wild appeal would be directed against the tithes which the people paid to the prelates and the abbots. The Saxon's doctrine being based wholly on the holy Scriptures, the peasant considered himself authorized in virtue of their text to break violently with his lord; hence that long war between the cottage and the castle. This it was that made Erasmus write sorrowfully to Luther: "You see that we are now reaping the fruits of what you sowed. You will not acknowledge the rebels; but they acknowledge you, and they know only too well that many of your disciples, who clothed themselves in the mantle of the Gospel, have been the instigators of this bloody rebellion. In your pamphlet against the peasants, you in vain endeavor to justify yourself. It is you who have raised the storm by your publications against the monks and the prelates, and you say that you fight for gospel liberty, and against the tyranny of the great! From the moment that you began your tragedy I foresaw the end of it."