It is difficult for the twentieth century to comprehend the violence and the deep feelings aroused by the controversies of the sixteenth. Anyone living after 1900 is aware of a mainly secularised and materially oriented world in which varied religious beliefs and gradations of disbelief are universal. Since Zwingli's day the Council of Trent and the wars of religion have been followed by eighteenth-century Enlightenment and nineteenth-century Evolution, Marxism and modernism. Zwingli and Luther were trained in the scholasticism of the later Middle Ages and could no more cast it off than even a comparable religious leader of today can escape from an education in which scientific criticism however superficial, and historical perspective however slight, have had their part. In 1529 the protagonists had all the world to gain: there were possibilities of Protestant union and of a compromise with Rome. The infidel Turk could be expelled and the light of the Gospel brought to Mohammedans, Hindus, Chinese and the Indians of the New World. If, and it was far from unthinkable, all Switzerland was united in a reformed faith to which Lutherans and Anabaptists could adhere, in alliance with a Protestant France and England, Europe might well be of one evangelical conviction.

The Marburg religious summit of 1529, important as it in the history of religion, was nevertheless also conditioned by the state of central European politics and the situation that year in Switzerland.