A new report from The Barna Group dated 10th of August, based on interviews with more than 3,000 adults, showed that conservative churches are larger in attendance.

On all nine of the belief statements tested, attenders of large churches were more likely than those engaged in a small or mid-sized congregation to give an orthodox biblical response—e.g., the Bible is totally accurate in all the principles it teaches, Satan is not merely symbolic but exists, Jesus led a sinless life, God is the all-knowing, all-powerful creator of the world who still rules the universe, etc. The point at which congregational belief profiles were mostly likely to diverge was when churches reached the 200-adult range. Those who attend churches of 1000 or more adults are significantly different from the congregations of those attending churches of as many as 200 adults in relation to six out of the 10 belief statements explored. Interestingly, the religious beliefs and behaviors of people who attend house churches, which average about 20 adults in attendance, are more similar to the results for large conventional churches (i.e., more than 500 adults) than they are to the outcomes among those who attend small conventional churches (i.e., less than 50 adults).

In addition, despite the substantial attention focused on Protestant mega-churches, such congregations only draw about 9% of adults who frequent a Protestant church. In contrast, 41% of adults attending a Protestant church associate with a congregation of 100 or fewer adults. An additional 23% can be found at churches of 101 to 200 adults, 18% associate with bodies of 201 to 499 adults, and 9% can be found in churches of 500 to 999 adults. Young adults were somewhat more likely to attend mega-churches than to affiliate with a congregation of any other size. In contrast, adults in their sixties or older were less likely to attend a church of 500 or more attenders than to regularly participate in a smaller church.