CHICAGO British comedian Sanderson Jones left a Christmas concert six years ago feeling uncomfortable - he no longer believed in God, but he sure liked singing carols.
Jones also missed other things about being in a church - the sense of community and time spent thinking about being a better person - just not the religion part.
"I wanted to celebrate being alive," said Jones, 32. "Being alive is one of the most magical, mystical things we've been given."
So Jones and his friend, actress Pippa Evans, got together in January in London for a first "Sunday Assembly," a service they say is not just for atheists, but for anyone who wants to "live better, help often and wonder more."
The London congregation now has 600 people, and Jones and Evans are taking the idea on a "road show" in the United Kingdom, Ireland, the U.S., Canada and Australia to help start new assemblies.
The U.S. tour starts in New York City on Monday followed by dates in Nashville, Chicago, Los Angeles and other cities listed at sundayassembly.com. The November 8 Chicago event has already filled up and has 100 people on a waiting list.
The Assembly idea may tap into a small but growing part of the U.S. population: the religiously unaffiliated, which includes atheists, has grown from 15 percent in 2007 to almost 20 percent, according to a 2012 Pew Research survey.
Jones cites research showing that people who go to church regularly tend to be wealthier, healthier and happier. He thinks this is because churches provide community and support in times of trouble. "We're just meeting a basic human need," Jones said.
Assembly meetings start out at once a month, and collections pay to rent the space.
The London Assembly has grown to twice-monthly meetings and has also done charity and community work - donating food and picking up litter in the neighborhood. A coat drive is planned for later this month.
Jones's "very religious" mother died when he was 10, and he later lost his faith. "I had to engage with the whole idea of life and death a lot earlier than most," he said.
But Jones said being an atheist doesn't define who he is - and the assemblies welcome believers as well as atheists.
"My granny believes in God - when I hang out with her I don't tell her she's stupid," Jones said. "There are so many more interesting conversations to have, when you look for what you have that's similar."
Jones noted that there are already secular and humanist societies - what's different about the Assembly is that it provides more of an emotional connection.
Cristina Traina, religion professor at Northwestern University, said she can see why some would be attracted to the Assembly, though she suspects the movement might be a "flash in the pan."
"It's very interesting that part of what they seem to miss is what Christians call liturgy - gathering to sing, to say something meaningful about the larger universe, to be inspired and made better in a group, not in your room," Traina said.
She noted that some people go to the orchestra or the theater for this kind of experience, and the Assembly would only make sense to people who have grounding in a church tradition. "It's not likely to be attractive to people who don't have that experience," Traina said.
The group is doing a "crowd funding" campaign to pay for its all-volunteer activities with the goal of raising $800,000 or 500,000 pounds - so far it's raised $40,000 (25,100 pounds), which hasn't pay the bills, Jones said.
Those who want to operate a Sunday Assembly must agree to its charter, which includes being inclusive, free, not-for-profit and independent, Jones said. This offers the group a "minimum amount of control needed to make sure it doesn't go wrong," said Jones. "If someone starts sacrificing pets, it really pees in the pool for everyone."
(Reporting by Mary Wisniewski; Editing by Greg McCune and Gunna Dickson)