As the Christian church grew larger and more powerful with each century, abuses of power inevitably set in. Chief among them were the sale of indulgences and the restriction of the Bible to Greek and Latin that most Christians could not read. Indeed, the whole superstructure of the church, with its hierarchy of popes, cardinals, bishops, and priests required to mediate the faithful’s relationship with God had become oppressive. Prior to the 16th century, a number of visionaries attempted to initiate reforms, but without much success. The Italian preacher Savonarola (1452-98) cleansed Florence of some of its worst abuses of church and state power for a time, but he was hanged and burned by the citizens of Florence for his efforts.
Martin Luther (1483-1546) had been an Augustinian monk, an ordained priest, and a doctor of theology at the University of Wittenberg in Germany when a passage in Paul’s Epistle to the Romans convinced him that forgiveness of sins could come only from the grace of God, and salvation, or justification, from faith in God rather than from sacramental works or indulgences. This idea of a direct relationship with the Deity became one of the cornerstones of the Protestant Reformation, which he set in motion when he nailed his famous 95 Theses (“On the Power of Indulgences”) to the door of Castle Church in Wittenberg in 1517. Like Luther, Jean Calvin in France developed the concept of justification by faith alone, with no reliance on the church to healp you earn your way to salvation. This belief is still at the core of mainline Protestantism as well as many unaffiliated Evangelical sects.
Luther intended only to open debate on the subject of indulgences, but when the pope summoned him to Rome to defend himself against charges of heresy, he chose to stay in Germany and call for a general reform of the Church. Luther advocated the abolition of priestly celibacy, monastic vows, fasting, masses and religious holidays, and the sale of indulgences. The pope officially excommunicated Luther in 1521, setting in motion a chain of events that led to the rise of Protestant sects.
At the heart of the Protestant reform was a return to the simplicity of the early Christians, following the New Testament rather than the interpretations of those texts by Church Fathers like Augustine and Aquinas, or the popes and their councils.