In our day, modern Protestants often define themselves in terms of doctrines that have a specifically anti-Catholic slant. The very term “Protestant” speaks to the reality that this movement was sparked by a protest that was originally related to some medieval Catholic abuses such as the widespread practice of selling indulgences. Indulgences were passes that, for a fee, guaranteed the buyer the right to be spared time in purgatory.

The sale of indulgences was not only viewed as spiritually beneficial to the purchaser, but was also a great fundraiser for the Roman Catholic Church. Reformer Martin Luther was especially appalled by the sale of the Peter Indulgence, the profits of which funded the Roman Catholic Church's completion of the construction of Saint Peter's Basilica in Rome.

Protestants have also pointed to the concern that was foremost on Martin Luther's mind — anxiety related to his own salvation. As Luther studied the Bible, he became increasingly convinced that salvation came through “grace alone and faith alone,” and not from purchasing indulgences from the Church. This newfound conviction brought him profound inner peace and courage, as well as the desire to share this good news with others.

Luther was a professor at a university in the German town of Witten berg. Many students responded enthusiastically to his teachings about the sufficiency of faith, grace, and Scripture for salvation. Much of what he taught, however, grew out of a personal reaction to a particular context and time in the history of the Roman Catholic Church.