From the biblical story of the Apostle Paul, a Damascus Road Conversion refers to an abrupt about-face on a serious issue of religion, politics, or philosophy. A single, dramatic event causes a person to be aligned with something they previously found anathema. For example, someone might experience a Damascus Road Conversion if they were protesting against an effort to convert parking lots to a neighborhood park; yet after listening to a city council meeting to discuss the plan, they become a spokesperson for the park.

The description of a Damascus Road Conversion originates with a biblical tale of a Roman citizen intent upon persecuting the Christians who became one of the most important prophets. Saul worked in Jerusalem, making it harder for Jews to worship in their new religion. As he was walking on the road to another city, Damascus, intending to imprison more Jews, a great flash of light accompanied God's voice. Saul's attention was brought to his vigorous persecution, and he was actually blinded by the brightness of the light. He continued to Damascus, where he regained his vision and was converted to another way of thinking, aligned with the Jews. He took on a new name, Paul, to indicate his complete transformation.

Common language has adopted this story to allude to the possibility that a person's fundamental outlook on life could be utterly changed in a single moment. Many changes occur gradually, such as developing different political beliefs from one's parents after going away to college. Yet once someone has actively worked against something, and all of a sudden realizes that they should be working just as actively in favor of it, one can say he or she has been converted to the new cause.

Interviews, articles, columns, and blogs frequently misuse "Damascus Road Conversion" by reducing it to a petty, insignificant change. It would not be appropriate to use, for instance, if you told somebody you didn't like a song you heard on the radio, but once you heard the whole album, you decided the musical artist was a genius. A true Damascus Road Conversion should be dramatic, deep, and long lasting, although not necessarily religious. A major career change, seeking another country's citizenship, or switching political parties would be better examples.