Luther, Martin | Internet Encyclopedia of Philosophy

On July 2, 1505, during a violent thunderstorm, Martin Luther vowed that he would become a monk. An excerpt from the article:

"In July of 1505, Martin was caught in a horrific thunderstorm. Afraid that he was going to die, he screamed out a vow, “Save me, St. Anna, and I shall become a monk.” St. Anna was the mother of the Virgin Mary and the patron saint of miners. Most argue that this commitment to become a monk could not have come out of thin air and instead represents an intensification experience in which an already formulated thought is expanded and deepened. On July 17th Luther entered the Augustinian Monastery at Erfurt.

The decision to enter the monastery was a difficult one. Martin knew that he would greatly disappoint his parents (which he did), but he also knew that one must keep a promise made to God. Beyond that, however, he also had strong internal reasons to join the monastery. Luther was haunted by insecurity about his salvation (he describes these insecurities in striking tones and calls them Anfectungen or Afflictions.) A monastery was the perfect place to find assurance."