Megachurches may be becoming de facto replacements for the more traditional denominations, researchers suggested.
Scott Thumma and Bird call it the rise of the "mini-denominations", although they are not necessarily fond of the term.
"Megachurches are creating around them structures and especially functions that once were done by the denominations," said Thumma, author of Beyond Megachurch Myths and a professor at Hartford Seminary in Connecticut, on Thursday.
Some of these structures include operating large networks of pastors and churches, providing clergy resources and music material, mobilising for community service and social justice efforts, and planting churches.
"They are creating alternative ways for churches and for religious people to get resources to do ministry, to do missions, to connect with other churches," noted Thumma.
"All the things that were typically done by a denominational form are being done at a local church level - if you can call a megachurch a local church," he added, noting the scale has shifted from the national hierarchical organisation to an informal, local church network.
Megachurches, however, are not the biggest threat to the life of denominations, Thumma indicated.
"In think it's probably less actual competition that's going to kill the denomination. There's a lot of other things that will kill the denominations," he said.
Other developing patterns among megachurches
In other findings, more megachurches are identifying themselves as "evangelical".
In 2000, less than half (48 per cent) chose the label "evangelical" but the number rose in 2008, with 65 per cent now taking on the label.
Fewer megachurches are choosing to identify themselves as "charismatic" or "pentecostal". Only 7 per cent chose the charismatic label in 2008 compared to 14 per cent in 2000, and only 4 per cent labelled themselves pentecostal compared to 11 per cent in 2000.
"The vast majority of megachurches have always held a conservative theological position, and this hasn't changed. But what has changed is a turn away from distinctive theological segments within conservative Protestantism toward a 'generic evangelicalism'," the study's authors stated.
A shift was also seen in political views.
The study stated that the majority of megachurch attendees are Republicans but "they are not the arch-conservatives many people portray them as".
Only 33 per cent described the majority of their church's attendees as predominantly conservative. Three years ago, 51 per cent had that label. Also, 44 per cent said their congregants are "somewhat on the conservative side" in 2008 compared to 33 per cent in 2005. And 17 per cent labelled their congregants as "right in the middle" while 11 per cent said the same three years ago.
Interestingly, the study also found that megachurches are not overtly political even during this year's election.
"The majority really want to stay out of politics as much as possible," said Thumma.
While keeping out of politics, megachurches are putting more emphasis on social justice and community service. In 2000, only 34 per cent affirmed their congregation was "working for social justice". In 2008, 51 per cent of churches affirmed this. Also in 2008, 73 per cent of the megachurches stated that community service activities were given a lot of programmatic emphasis in the past year or were a specialty of the church.
The megachurch study is based on a national study of America's roughly 1,200 megachurches with approximately one third returning a usable response to a survey conducted between February and August of 2008. Comparisons were given to similar national studies in 2000 and 20005.
