In the late 15th century, when Martin Luther was born and grew up, death was very much present. Family, friends, and neighbors seldom reached what we today would consider a middle age, and women of childbearing age were at special risk. Catholic clergy took pains to offer Christians at every social level ways in which they could prepare themselves for the happiest possible afterlife.
When Martin Luther joined the order of Augustinian Eremite Friars in 1505, he had never read a Bible. He now gained access to one that the brothers of the Erfurt house had in their library. Luther read it intently. He found that numerous Catholic points of theology and practice were not validated in scripture. In 1517, he chose the issue of indulgences on which to attack church practice, in view of the fact that the ordinary people in Wittenberg to whom he regularly preached—he was not their pastor—sacrificed a great deal to pay for certificates of indulgence.
As a result of his encounter with the Bible, Luther proceeded to dismantle long-standing Catholic belief concerning death and treatment of the dead. He disqualified the Virgin, saints, and priests as intermediaries between individual souls and God. He insisted that as a result of the Fall of Adam and Eve, humans could not perform good deeds to earn themselves entry to Heaven. They had, instead, to rely on the atoning power of Christ’s death on the cross to pay the penalties that they deserved for their continual sinning. Those who had faith in the atonement would be saved. Justification by faith supplanted a theology of justification by good works.
Etc. Do enjoy.