David Ray Wilkerson was an American Christian evangelist, best known for his book The Cross and the Switchblade. He was the founder of the addiction recovery program Teen Challenge, and founding pastor of the non-denominational Times Square Church in New York City. Wilkerson's widely distributed sermons, such as "A Call to Anguish", are known for being direct and frank against apostasy and serious about making the commitment to obey Jesus' teachings.