"As one looks over the history of Christendom, it seems that there is a crisis about every five hundred years. The first cycle of five hundred years was the fall of Rome, when God raised up the great Pontiff Gregory the Great, who had been a senator in Rome. He became a Benedictine monk and then set about conversion of the barbarians and prepared the way for a Christian Europe. The second cycle of five hundred years brings us roughly to the year 1000, when there was the Eastern schism, but also the decline of holiness in the Church. Three dominant evils prevailed - clerical concubinage, simony or the buying and selling of ecclesiastical offices, and the naming of bishops by princes and kings. Gregory VII, who was a Benedictine, was raised by God to heal that crisis against much opposition from within and prepared the way for the great medieval civilization. In the third cycle of five hundred years, there was a breakup of Christian unity. Clergy again became corrupt, nuns became secular and everyone recognized the need of reform. Some undertook to reform the Faith. There was nothing wrong with the Faith. What needed reformation was behavior. The great Dominican Pontiff, Pius V, saved the Church by applying the reforms of the Council of Trent and by establishing missionary activity throughout the world. Now we are in the fourth cycle of five hundred years, with two world wars in twenty-one years, and the universal dread of nuclear incineration. This time God has given us John Paul II, who has drawn the attention of the world to himself as no human being has done in history."
-Treasure in Clay by Archbishop Fulton J. Sheen, c. 1980.