I was in Peckham twice on Thursday. The first time I visited the outstanding local council gym where a friend training there said that although he loves the building, a great skylighted modern glory, in the evenings it becomes a threatening place. Muscled-up black guys let colossal weights crash down, a complete gym nono that is dangerous, destructive and alarming for everyone else. “But no one ever tells them to stop,” he said. “Even the staff here are too scared.”

Walking home along one of Peckham’s elegant Regency streets, occupied by boho artists and media folks, a young black man approaches me. He says he’s been waiting for a friend for 30 minutes, can I please call him on my phone? He seems agitated but unthreatening. I lie that I don’t have my mobile with me and he wanders off while I reflect that if he’d been a white woman, I’d have probably made that call.

The second time I visited Peckham was at dusk, not an hour I’ve ever lingered alone when the streets around Rye Lane cease to belong to the halal butchers, pound-shop owners, young mums with buggies, sturdy Caribbean ladies in church hats or the teens spilling out of Primark. Especially not lately, after three fatal shootings in a few weeks. Or is it more now? South London is starting to lose count.

It was the genius of the march against gun crime that it gathered after dark: the daytime people’s defiance of the gangs of night. And the crowd of 1,000-plus beneath the library — the last place Damilola Taylor was seen alive — for all its grim mission, and the presence of relatives of the dead, vibrated with excitement, daring even.

This was like no other protest I’ve ever attended, being 100 per cent unashamedly a Christian event, taking no heed of Peckham’s 10 per cent of Muslims let alone the smattering of white, secular liberals anxious to show solidarity but slightly uncomfortable joining in a chorus of “put down your guns and pick up the Bible”.

Organised by an evangelical alliance of churches, many but not all of which are black-dominated, it was compered by messianic preachers who bore witness in Baptist hell-fire style. This and the low, dignified, singing of Amazing Grace and We Shall Overcome lent it the quality of an American civil rights rally. The non-born-again among the speakers, Cressida Dick, the Met’s new deputy chief commissioner, and Vernon Coaker, the Home Office minister, (who, big respect, walked the entire march, his suit splattered in bird droppings, then returned to Westminster by Tube) judged the crowd and kept it short.

But behind me were dissenting, fast-talking, angry black women: “Jesus ain’t coming to Peckham,” said one, who runs a community project for single mothers. “The churches all down Peckham Road are businesses, filling their coffers with black people’s money, the minister’s BMW parked outside. They’re using gun crime for a recruitment drive.” Her friend, another community worker, chimed in: “Why don’t the churches open their doors to young men, teach them skills, keep them out of prison, take our young girls to the STD clinics, instead of shoving Jesus down their throats?”

The pair looked on as Lee Jasper, the oleaginous race relations adviser to the Mayor of London (Ken, as always, was indisposed), shook hands beside a high-ranking black police officer and local pastors. “Plastic black people,” said one. “A photo opportunity out of dead children.”

But then we were off, a thousand of us, maybe more, marching along roads between New Cross and Camberwell where police say guns are delivered on mopeds like pizzas, pausing at the spot where Javarie Crighton was stabbed to death. Not scared, not looking over our shoulders, watchful of handbags but exhilarated by waves from bus passengers, toots from drivers suspended in jams. Waiters, launderette workers, customers in black barbers’ shops and kebab houses came on to the street to gawp.

But at the fringes of the march were the only group little represented in the crowd of young and old women, children and older men. Young black men looked on, took leaflets, said nothing.

At Camberwell Green I talked to a bunch hanging by McDonalds. Why hadn’t they joined in? “Peckham for ever!” exclaimed one unprompted. He’d followed the route for the first mile or so, but was going no farther. “I ain’t going to Brixton. I don’t agree with the march going there.” But weren’t two boys shot there before Christmas? “Yeah, but they didn’t die.” He wasn’t in a gang, he said, but his group had reached the end of their home turf, the Lambeth-Southwark border. To go any farther would risk trouble, another shooting.

A young woman came over from the Victory Outreach Church, an American group set up by ex-gang members. She asked the youths — all on jobseeker’s allowance and one who claimed never to have been to school — if they’d like to go on a mentoring programme. “Do you get paid for it?” asked Peckham For Ever.

As we continued without them, the march, now tailed by a pair of Hummers, headed past Southwyck House, the brutalist council estate built by John Major, that resembles the prison blocks so many of its children end up in. I wouldn’t walk around there even in daylight. But viewed from this all-powerful crowd, the youths who lurked at the bottom of mean-windowed blocks, for whom a weapon is no more than a phone call away, did not seem menacing.

Instead you saw them for what they are: young men at the peak of their physical strength, growing up in a ghetto (an unfashionable word but the right one), without fathers or role models of any kind — since all who succeed gladly flee — bored, so bored, with nowhere to direct their energy, testosterone or their innate desire to test themselves, their bodies, their bravery, except against each other on the streets.

How do you reach them? What can they be offered when the unskilled jobs they once would have taken go to Poles with degrees and, in any case, would not buy them the tawdry logoed bling they are led to believe makes them a big man? The options that day were Tony Blair’s tougher sentences on 18-21 year olds carrying weapons — opening new opportunities for the younger gun-runner — or the Lord’s word.

What must it be like to be so powerful yet so loathed and feared? I wonder if the freedom to crash 50 kilo weights without sanction is worth the price that those around you won’t stop to grant the merest human kindness.

Times Recommends

• Fragility always gets my sympathy vote
• Double it and you get the real jobless total
• Has al-Megrahi paid his council tax?