In the age of the booming mega-church, some people are bucking the trend and deciding that, if size matters, smaller is better:

Jason Kilp had a short commute to church one recent Sunday. He walked about 15 feet from the bedroom of his Anaheim apartment to a small worship service in the living room.

“It’s intimate,” the 24-year-old graphic design student said. Unlike gatherings he and his wife have attended at a 4,000-member mega-church in Irvine, Kilp said, “this is like a conversation. It’s somebody talking to you.”

The couple are part of a growing movement, mostly among evangelical and born-again Christians, that, depending on who’s talking, represents either a second Protestant reformation or a sellout of biblical principles.

The trend goes by several names: house churches, living-room churches, the underground church, the organic church, the simple church, church without walls. Although they disagree on whether it’s a good thing, proponents and detractors say that going to church in a home has the potential of forever changing the way Christians worship.

“We are at the initiation point of a transformational shift,” said George Barna, author of the book “Revolution,” about the changing nature of worship, and founding director of the Barna Group, a Ventura-based research firm that tracks religious trends.

A 2006 survey by his firm — tracking developments for use by researchers and the media — concluded that 9% of U.S. adults attend house churches weekly, a ninefold increase from the previous decade, and that roughly 70 million Americans have experienced a home service.

Those most likely to attend house churches, according to phone interviews with more than 5,000 adults nationwide, are men, families that home-school their children, residents of the West and nonwhites, while those least likely to attend include women, people older than 60 and Midwesterners.

“We predict that by the year 2025, the market share of conventional churches will be cut in half,” Barna said. “People are creating a new form of church, and it’s really exciting.”

Will this sort of worship spread to Catholicism? I remember, back in the ’70s, attending one or two “home masses,” with maybe a dozen people gathered around a dining room table. (Guitars may have been involved. I don’t remember.) But part of being a community of faith is being a community, and sharing communion — in every sense of the word. Is smaller really better? I’m not so sure.