Wilkerson was a pastor in Pennsylvania. Around 1960 he started a ministry in New York City to help and evangelize teenagers, who were involved in drugs and crime. In 1960, he founded for that reason the Christian relief organization Teen Challenge. With the Sherrills he wrote a book about his experiences called The Cross and the Switchblade (1962).
Some years later, in 1967, he founded Youth Crusades, again aimed at teenagers but this time to prevent them from the bad things mentioned above.
In 1971, he founded again a Christian organization, World Challenge, to evangelize worldwide.
Wilkerson wrote several Christian books, like the already mentioned The Cross and the Switchblade (1962) and the very impressive The Vision (1974). Last book and its successor (The Vision and Beyond, 2003) are dealing with divine prophecies about severe misconduct, problems and disasters the world is facing in the future (and already partly happening); he also revealed that the so-called "Number of the Beast" (Antichrist) will be composed of a combination of three times six numbers. He also wrote about other divine prophecies such as riots and arsons cities in the United States (especially New York City) but also worldwide are going to endure in the future because of their sinful behavior, and countries going bankrupt causing shopping and money problems worldwide.