Echoing with joyful song and with a congregation bent on leading better lives, this London church is like any other -- except there's no mention of God.
Britain's atheist church is barely three months old but it already has more "worshippers" than can fit into its services, while more than 200 non-believers worldwide have contacted organisers to ask how they can set up their own branch.
Officially named The Sunday Assembly, the church was the brainchild of Pippa Evans and Sanderson Jones, two comedians who suspected there might be an appetite for atheist gatherings that borrowed a few aspects of religious worship.
Held in an airy, ramshackle former church in north London, their quirky monthly meetings combine music, speeches and moral pondering with large doses of humour.
"There's so much about Church that has nothing to do with God -- it's about meeting people, it's about thinking about improving your life," said Jones, a gregarious 32-year-old with a bushy beard and a laugh like a thunderclap.
The Sunday Assembly's central tenets are to "help often, live better and wonder more" -- themes that would not be out of keeping with the teachings of any major world religion.
At last Sunday's service, which had a volunteering theme, songs included "Help" by the Beatles and "Holding Out For A Hero" by Bonnie Tyler.
The "sermon" was given by the founder of an education charity, while in a section called Pippa Is Trying Her Best, Evans had the congregation in stitches as she reported on her attempts at voluntary work.
The service ended with big cheers and -- this is Britain, after all -- shouts of "Who would like a cup of tea?"
Like many Western countries, Britain is becoming an increasingly faithless nation.
While a majority still consider themselves Christians, census data revealed in December that their numbers plummeted from 72 percent in 2001 to 59 percent in 2011.
The proportion of Britons with no religion, meanwhile, shot up from 15 percent to 25 percent over the same period.
But the Sunday Assembly's success -- 400 Londoners packed into last week's two services, while 60 had to be turned away at the door -- suggests many urban atheists crave the sense of community that comes with joining a church.
"You can spend all day in London not talking to anyone," said Evans. "I think people really want somewhere they can go and meet other people, which doesn't involve drinking and which you don't have to pay to get into."
It's an idea that is catching the attention of atheists further field.
Jones reels off the locations of would-be atheist "vicars" who have asked to set up new branches.
"Colombia, Bali, Mexico, Houston, Silicon Valley, Philadelphia, Ohio, Calgary, all across Britain, The Hague, Vienna... It's so ludicrously exciting that my head occasionally -- literally -- spins round."
The pair cheerfully admit that they have "ripped off" many elements of their services from the Christian Church. "You're asking people to do new things, so it makes sense for it to be familiar," said Jones.
Religious people have been broadly supportive of the aims of the atheist church. "The only thing is, they've said they'll have to think about what to do if it gets bigger," Evans laughed.
"Actually, the biggest aggression towards us has probably been from atheists saying that we're ruining atheism and not not believing in God properly. So that's quite funny."
The assembly met the approval of local vicar Dave Tomlinson, who came from his church two miles away to see what his new rivals were up to.
"Being here, I felt there was as much of what I call 'God' as there was in my own church this morning," he said. "Everything we've said here would be completely at home in my church. I hope it grows and sustains."
The second Sunday Assembly launches in the Scottish city of Glasgow at the end of March, while Evans will open an Australian branch in April.
She and Jones say they don't want to exert too much control over any new assemblies -- but they will keep a watchful eye over them.
"We only need one child sacrifice at a Sunday Assembly to spoil it for everyone," Jones joked.
As for how far the idea could eventually spread, the pair are in the dark.
"Who knows?" said Evans. "We have no idea. We're just enjoying finding out what it is."