By Myriam Renaud | Affiliated Faculty of Bioethics, Religion, and Society, Department of Religious Studies, DePaul University

In 1517, the German theologian Martin Luther nailed 95 theses to Wittenberg’s Castle Church door, attacking indulgences, a Catholic practice that, according to church teachings, can reduce or eliminate punishment for sin. Starting in the 11th century, the church offered indulgences to those who joined the Crusades and later sold certificates of indulgences to raise funds, giving rise to the abusive marketing tactics criticized by Luther.