David Wilkerson (May 19, 1931 - 27 April, 2011) was a Christian evangelist perhaps best known for his 1963 book, The Cross and the Switchblade, his 1973 book The Vision, and for founding Teen Challenge. Prior to his death in a car-crash in April 2011, he had been making wild prophecies of an imminent "earth-shattering calamity" complete with floods, fire, war, riots, and other
everyday occurrences doom'n'gloom. He claimed that the current economic downturn is neither a recession nor a depression, but is "God's wrath" to judge a sinful world.
 Gang ministry
Wilkerson was an Assemblies of God minister in Pennsylvania who left his rural church for New York City during the 1950s, claiming a vision from God to reach out to gang members. His best known convert was Nicky Cruz, a gang member who later became an evangelist himself. His book The Cross and the Switchblade tells the story of him going to New York, preaching to gang members, winning over Nicky Cruz, and founding Teen Challenge. The book is filled with odd coincidences the author attributes to miracles of God, mostly having to do with the exact amount of fundraising he needed at any given time coming through after he prayed for it. The book later became a 1970 movie starring Pat Boone as Wilkerson and Eric Estrada as Cruz, along with the then-obligatory comic-book adaptation by Spire Christian Comics (Cruz is supposed to be telling his own version of the book from his POV in a new movie, but nothing has come of it yet.)
Teen Challenge has since become several organizations, Teen Challenge USA, Global Teen Challenge, and World Challenge. It has been characterized as a drug and alcohol recovery program and a program for "recovery" of gang members and prostitutes among others, but its main goal and method is evangelism rather than treatment. In The Cross and the Switchblade, Wilkerson claims the key factor in recovery among former drug addicts and gang members is receiving the "baptism of the Holy Spirit" with the "initial evidence of speaking in tongues". Teen Challenge was one of the organizations cited during the early 2000s debate over federal funding for faith based charities. They were challenged during Congressional hearings on such funding because they do not hire non-Christians as employees. Teen Challenge has also come under fire for promoting reparative therapy.
 Other books
David Wilkerson was the author of over 30 books. Among the better known are:
The Vision, a 1973 book of prophecies Wilkerson claims to have been given from God. The general theme is America is about to undergo a moral breakdown, with pornography openly shown on cable TV, widespread acceptance of homosexuality, a "new sex drug" that would lead thousands into promiscuous lifestyles, and hatred and persecution towards Christians with a "hate Christ" movement. He also prophesied the Iron Curtain would come down but only temporarily, just long enough for the Gospel of Christ to be spread throughout Eastern Europe, and then would go back up. Lest one think everything in this book came to pass, much of it is odd prophecies of things like mysterious explosions in the skies, chemtrails, famine, floods, economic depression, the collapse of the dollar and a new one-world money system, nude dancing in the church, and worse, that did not. As with many such non-specific prophecies it is possible to retroactively shoehorn events since as their fulfillment even though they didn't come about exactly as predicted in the book: a "new sex drug" could be MDMA ("ecstasy"), nitrite inhalants ("poppers") or viagra and "famine" could be the recent heat records being broken throughout America; the Iron Curtain coming down (the Iron Curtain has been down for 20 years now but the eastern country of Russia is standing strong while the western currencies fall which could lead to a new iron curtain.)
Set the Trumpet to Thy Mouth makes a demand for a "holiness" lifestyle among Christians and is a rant against Christians having television sets in their homes, Christian Rock, social consumption of alcohol, and other purported compromises with the devil. Regarding Christian Rock, Wilkerson begins the chapter with a tirade against the leather and studs clothing of the homosexual BDSM community in San Francisco, claims he was able to detect widespread demonic possession among that community when he was trying to witness to them on the street, and then imagine his profound shock when he saw Christian heavy metal and punk bands wearing the same clothing. Rock & roll, according to Wilkerson, is the devil's music born straight out of the pit of Hell and Christians should not be bringing it into the church, because God hates it. Same goes for television and alcohol. Bad, bad, bad. David Wilkerson has spent hours at a time "prostrating himself before God" seeking His will on these matters, so he should know. Published in 1985 a year before the Jim Bakker and Jimmy Swaggart scandals broke, this book also stated that God was about to clean house and bring televangelists down who were involved in adultery and/or stealing money to build big amusement parks, so maybe he was right about a few things here.
 Doom and gloom
The Vision (1973) predicted a worldwide economic depression. Nothing happened. So did his late 1990s book, God's Plan to Protect His People in the Coming Depression, which encouraged Christians to stockpile the usual stuff. Nothing happened.
On March 7, 2009 he issued a new urgent prophecy direct from the Holy Spirit that "An earth-shattering calamity is about to happen...It will engulf the whole megaplex, including areas of New Jersey and Connecticut. Major cities all across America will experience riots and blazing fires – such as we saw in Watts, Los Angeles, years ago...There will be riots and fires in cities worldwide. There will be looting – including Times Square, New York City. What we are experiencing now is not a recession, not even a depression. We are under God’s wrath."
In his book The Vision he predicted collapse of the U.S. dollar.