Many basic questions surround the Reformation. What were its causes? Was it precipitated by the Zeitgeist prevailing in Europe, so that there would have been a religious upheaval even if Luther or Zwingli had died in their cradles? Was the Reformation an authentically religious phenomenon, or the result of certain political, social, or economic developments? Was it 'medieval' or 'modern' in its orientation? What was the teaching of the Reformers? What was the significance of the Reformation? The measure of scholarly agreement with respect to these questions differs; far from offering definitive answers, we can here only call attention to their persistent presence....
'When the reformers who had first ventured a new interpretation of the gospel had passed from the scene, the question which had haunted the Reformation from its very inception--where is truth?--was still contested by the proponents of the old and the new faith. But one fact was beyond dispute: Western Christendom was tragically divided...into no less than five [religious factions]....Though these divisions were the result of intense religious conviction, they could not help but lessen the intensity of religious belief in Europe. The Reformation of the sixteenth century was the last period in the history of Western civilization when men were preoccupied with religion, argued it, fought and even died for it. Its consequences are still with us.' --Hans J. Hillerbrand