The Ninety-five Theses or as they we titled, “Disputation on the Power and Efficacy of Indulgences is a list of propositions for an academic disputation” written in 1517 by Martin Luther, professor of moral theology at the University of Wittenberg, Germany.

They advance Luther’s positions against what he saw as the abuse of the practice of clergy selling plenary indulgences, which were certificates believed to reduce the temporal punishment in purgatory for sins committed by the purchasers or their loved ones. In the Theses, Luther claimed that the repentance required by Christ in order for sins to be forgiven involves only inner contrition, and that sacramental confession is unnecessary. He argued that indulgences led Christians to avoid true repentance and sorrow for sin, believing that they could forgo it by obtaining an indulgence. These indulgences, according to Luther, discouraged Christians from giving to the poor and performing other acts of mercy, which he attributed to a belief that indulgence certificates were more spiritually valuable (despite the fact that indulgences were granted for such actions). Though Luther claimed that his positions on indulgences accorded with those of the Pope, the Theses challenge a 14th-century papal bull stating that the pope could use the treasury of merit and the good deeds of past saints to forgive temporal punishment for sins. The Theses are framed as propositions to be argued in debate rather than necessarily representing Luther’s opinions, but Luther later clarified his views in the Explanations of the Disputation Concerning the Value of Indulgences.

Luther sent the Theses enclosed with a letter to Albert of Brandenburg, Archbishop of Mainz, on 31 October 1517, a date now considered the start of the Reformation and commemorated annually as Reformation Day. Luther may have also posted the Ninety-five Theses on the door of All Saints’ Church and other churches in Wittenberg, in accordance with University custom, on 31 October or in mid-November. The Theses were quickly reprinted and translated, and distributed throughout Germany and Europe. They initiated a pamphlet war with the indulgence preacher Johann Tetzel, which spread Luther’s fame even further. Luther’s ecclesiastical superiors had him tried for heresy, which culminated in his excommunication in 1521. Though the Theses were the start of the Reformation, Luther did not consider indulgences to be as important as other theological matters which would divide the church, such as justification by faith alone and the bondage of the will. His breakthrough on these issues would come later, and he did not see the writing of the Theses as the point at which his beliefs diverged from those of the Roman Catholic Church.

Information and teaching on the Reformation
A Survey of Church History – Introduction to the reformation