Catholicism has survived for almost 2,000 years with certain core values intact and with a basic framework that has also survived in spite of massive historical changes, countless social movements, defections from the Church and the creation of new sects to compete, and other forces that have challenged the power of the Church, many of its teachings, its structure and administration, and other aspects of the Catholic Church and its beliefs. From time to time, the challenges have become more severe, to be followed eventually by periods of cultural revitalization to which the church has adapted even as it has at times led such an effort. One of the major challenges to Catholic power came during the Reformation with the efforts of Martin Luther, John Calvin, and Ulrich Zwingli to reform perceived excesses in the Catholic Church.
Martin Luther challenged the authority of the Catholic Church when he placed his theses on the church door, and in so doing he empowered a movement away from the strictness of Catholic teaching and from the idea that communion with God required the intercession of the papacy and the religious structure of a Church. Luther was reacting to a variety of specific abuses in the Catholic hierarchy and was also acting out differences he had with Church teachings. His protest challenged the rule of the Catholic Church, but it was not at all irreligious and in fact affirmed the importance of religion and religious belief. Luther's was not the first protest against the Catholic Church and its abuses, but he succeeded where others had failed because he was one of the people and spoke their language. The most important tenet in Catholic Church doctrine was the requirement of obedience, but for Luther what as important was not obedience but truth. By his discovery of God, Luther discovered the importance of truth and the need for elevating truth to the highest level:
He had discovered the freedom of a Christian...