The Reformation of the sixteenth century is, next to the introduction of Christianity, the greatest event in history. It marks the end of the Middle Ages and the beginning of modern times. Starting from religion, it gave, directly or indirectly, a mighty impulse to every forward movement, and made Protestantism the chief propelling force in the history of modern civilization. –History of the Christian Church, Philip Chaff, 1888 In this passage, Chaff sees the Reformation as a religious war. a challenge to Christianity. a modernizing force. a challenge to Protestantism.