A researcher is forecasting that, by 2025, the “market share” of conventional churches will be cut in half. George Barna, founding director of the Barna Group, a Ventura-based firm that researches religious trends, says people are creating a new form of church that favors small-group sharing and leaves large structured churches and their rituals behind.
 
Barna has written a book, Revolution, about this new form of church, which goes by various names -- house church, living room church, underground church. He says house churches reflect a philosophy that values relationships over doctrine and tradition, reports the California Catholic Daily.
 
People gather in homes in small groups averaging anywhere from a dozen to twice that number, where they worship, pray, and engage in Bible reading.
 
A 2006 Barna Group survey estimated that 9 percent of U.S. adults attend house churches weekly, nine times the number that did so in the 1990s. Proponents of the home church say it is the way the early Christians met.
 
But critics say the phenomenon leads to insular groups that develop club mindsets that are not open to the wider world.

Home churches reflect a Protestant Evangelical mindset in that their ultimate authority is the Bible and they don’t depend on ordained clergy to provide ritual or give them sacraments, according to Penn State University sociology and religious studies Roger Finke. 

Several Catholics have also taken to home churches, leaving behind their parishes, reports the California Catholic Daily.