By Dominic Casciani
BBC News Online community affairs reporter
They're on a mission for God - and about to join the front line of Britain's war against drugs crime.
Pastor Les Isaac at work
This week, a dozen seemingly unassuming Christians sat in a small office in London's Angell Town housing estate, near Brixton, and watched a video about how bad things are in the area.
This group will soon patrol some of the capital's most dangerous neighbourhoods - areas blighted by drugs, gangs and, increasingly, guns. They are the UK's first street pastors.
Last year gun crime rose by more than a third, but it took the New Year deaths of two teenage girls in Birmingham to bring home the extent of this social crisis.
For Pastor Les Isaac, of the Ascension Trust, it's nothing new. He's spent 25 years trying to help young men and women out of the clutches of crime. He believes street pastors will be a critical tool in rebuilding communities.
The initiative began in Kingston, Jamaica, when churches banded together to take their values onto the streets.
The aim was to target those at risk of gang membership, drugs, guns and violence.
In effect, street pastoring is a visible and more confrontational form of social work with a Christian flavour.
Recruits: Herlene Williams, Andrew Dwyer and Herma Buttler
Its emphasis is on preventing crime by building bridges between the offender and the community from which they have become detached. This may be as simple as talking to a drug dealer or as complex as sticking with someone as they try to sort their life out.
On 31 March, the Home Office begins a guns amnesty. The Ascension Trust, the cross-denominational Christian activist group running street pastoring, hopes it will maintain the momentum for change.
"Street pastoring is on a different level to anything that someone may do in their church already," says Pastor Les. "The volunteer pastors will face enormous challenges."
Cure urban ills
The first teams take to London's streets this year and Birmingham and Manchester are set to follow suit. Street pastors, wearing blue jackets and baseball caps, will work target areas at weekends.
They will be expected to know the pubs, clubs and parties. They will talk to everyone from dealers to those just hanging around. They will be on estates where bored youngsters find respect in joining a gang.
Pastor Les says he has felt his life threatened just twice in 25 years of outreach work within communities.
On both occasions, he believes trust was the key to defusing the situation. So today, if he sees someone smoking drugs, he does not condemn it. Rather he works at building up their respect.
"When you invade someone's personal space, how you react in those first 30 seconds determines whether or not you are going to be allowed to stay there," he says.
The Ascension Trust is not seeking the support of the authorities as many of those they are trying to reach do not trust the police. But it will expect their tacit acknowledgement that street pastoring has a role, because it will grow out of communities.
One of the inevitable criticisms is that these are well-meaning Christians hopelessly out of their depth.
"I thought a lot about committing to this work because of the kind of people I have come into contact with within the church," says trainee Andrew Dwyer.
"We don't preach to them. The first thing we do when they ask for help in the church is to try and make sure they're safe. Taking this out on to the streets makes sense."
Pastor Les says: "The guys in the streets know they are in a mess. Their communities know they are in a mess. But taking them straight into a church won't help because what happens when they leave the church on a Sunday afternoon? You cannot speak to someone with an empty stomach."
The most important way to fill that stomach, he says, is in addressing self-esteem.
Unemployed young men who have been thrown out of school find it in gang membership without having thought about the consequences.
"If we can intercept them, then they have a chance. If they get involved with the police, then we're talking prison and prison becomes their university. If you engage with someone, and you don't follow it up, then you are blowing it for all time because you are just another person to have let them down."
Trainee Herlene Williams, of the New Life Assembly church in Camberwell, south-east London, wants to help turn around troubled lives.
"I spent a lot of my childhood growing up on these streets. Today I see girls having babies when they are 12 or 13 and they are not even capable of being mothers. There's no respect in the home. No-one is surprised anymore by anything. No-one is shocked."
Pastor Les says: "There are those who say we have lost two generations of young men and the only thing we can do is lock them up. I disagree. There has always got to be hope."