A documentary on evangelising young people entitled "Jesus Camp" has launched, featuring kids praying and worshipping at Bible camps and youth events in the US.

|PIC1|But the documentary has caused a scare to some audiences for its raw depiction of white evangelical children being 'radically trained' to lay down their lives for the gospel.

Many are condemning Pastor Becky Fischer, director of the initiative, accusing her of 'manipulating' or 'brainwashing' children.

The film features kids shouting out for forgiveness and sobbing over social issues such as abortion and war. 'Air America" radio host Mike Papantonio is among many who disagree with the tactics used at the camp.

"I think when you look at what occurs in the camp, there is a use of guilt. There is a use of shame," Papantonio said. "That is not directed all at Becky. I mean, what is a 5-year-old capable in ways of sin? Maybe stealing an Oreo from a cookie jar."

Papantonio asked Fischer why children needed to be so emotional at such a young age.

"One repetitive theme is a child crying, a child laying out on the ground and crying. Well, what are they crying about?" he asked. "Why does a 5-year-old feel like it is necessary to cry about their spirituality?"

"I do not use guilt. I do not use shame or manipulation in those ways," Fischer said. "This is a very intense moment. These children are passionate about their faith in Jesus Christ. Most people don't really have much emotion going on in their religion at all."

Over the past decade and a half, enrolment at Christian colleges is up 70 per cent in the US. Sales of Christian music in the US are up 300 per cent. Tens of thousands of youth pastors have been trained.

Young people are the majority who are targeted through Christian music festivals, skateboard competitions and rodeos.

"I think there is a push right now in a lot of evangelical churches to definitely keep the teenagers and keep the children in the faith," said Heidi Ewing, co-director of "Jesus Camp." "And this is one version of that attempt."

This camp is, by many accounts, a small - and perhaps extreme - slice of what some say is a growing, intensifying evangelical youth movement.