I have heard a lot of obvious nonsense about this, but hard facts and reliable studies are spotty. So, here are my best estimates about the demographics of Christianity in the U.S. (I’m sorry I can’t do other countries right now but the U.S. is hard enough!)
“Number of people going to church” is actually comparatively easy, because there are several decent studies arguing about it. The Gallup Poll says 41 to 43%, which is pretty surely about double the actual number; but it means something, that is, people who think they should attend church every week. In fact, a Harris poll determined that 26% go every week and another 9% go once or twice a month, which is getting pretty close to the Gallup number if you substitute “every month” for “every week”. Catholic participation is a little higher than overall Protestant participation. These figures approximately agree with an in-depth study of a limited sample done by Kirk Hadaway and P.L. Marler in 1998, Did You Really Go to Church this Week.
Still, that’s better than we might have imagined. More than a third of the population are practicing Christians. Of course there are devout Christians who don’t go to church often, and complete hypocrites and/or agnostics who do, but the figures are so approximate that we can just say the two groups balance out.
Which denominations are growing and which are declining?
The denominations that are in the steepest decline are what pollsters identify as mainstream Protestant churches; and in fact, churches identified as “liberal” — by the Hartford Institute (Episcopal, Presbyterian-USA, Church of Christ) are in steepest decline. They lost about 40% of their membership 1965-2005, a period when the total population increased about 70%. The trend actually might be accelerating, as the last reported year (2010) from the National Council of Churches showed a one-year decline of 3.5%, 2.7%, and 2%, respectively. The Evangelical Lutheran Church in America, which is mixed liberal/moderate (due to congregational governance) reported the largest loss of all surveyed, 5.9%.
“Moderate” mainstream churches are declining in total membership, but more slowly. This is primarily the United Methodist Church, down about 1%; some smaller denominations and the Lutherans (Missouri Synod), who would be halfway between moderate and conservative, also showed declines of about 1% for the year, as did three Baptist denominations other than Southern Baptist.
“Conservative” mainstream Protestant churches are primarily two Baptist organizations: the Southern Baptists, the largest Protestant denomination, have shown a big increase (50%) in the past 40 years but were flat in 2010; the American Baptist Conference, which is primarily African-American and somewhat more moderate, grew 4% in 2010. The little Christian & Missionary Alliance (where Billy Graham first preached) has grown enormously (400%) since 1960 but 2010 growth was not reported.
“Holding even” includes the Catholic Church, but it would seem that a decline in native membership is being masked by growth from a large number of Hispanic Catholic immigrants. I certainly know a lot of Catholics in the northeast whose parents were fairly observant but who have abandoned the church themselves; in my case, friends of Irish and Italian heritage.
The churches that are booming are, first off, what you might call two “sect” churches, whose doctrine includes writings of prophets in the past century or two: Church of Latter Day Saints (Mormons) and Seventh Day Adventists are showing solid growth. Jehovah’s Witnesses are increasing solidly. Secondly, Pentecostal denominations are growing, including the several Church of God denominations, Pentecostal Assemblies, Assemblies of God, and even the Salvation Army.
The unknown variable in all of this are independent evangelical churches, which are very difficult to count and categorize by their nature, ie. because they are not gathered into denominations. The National Council of Churches’ statistics simply ignore them, because NCC reporting is done by denomination; however, two sources (both sponsored by conservative church groups) state that these churches now make up the third largest group of churches in the U.S., after the Catholic and Southern Baptist Churches.
A Baylor University report (which must be considered potentially biased) states that independent evangelical church growth is enormous, about 150% in the past 40 years. They surmise that much of the growth comes at the expense of mainline Protestant churches, as more Biblically-oriented or “conservative” Episcopalians, Presbyterians, etc., leave to join independent evangelical churches. (The report is the first link below.) This certainly does happen — there is a large independent evangelical church here in Atlanta that was started by disaffected Episcopalians — but there has been no reliable quantification of it.
- Baylor Report
- Fast Facts about Religion, from the Hartford Institute
- National Council of Churches
- Trends in Large US Church
Membership from 1960 from Demographia
- U.S. Religion Census: Religious Congregations and Membership Study, 2010
Here are some interesting facts taken from #5. Roulette County, N.D., is 100% Catholic. There are now more Muslims than Jews in Florida. The only state in the U.S. where Hindus are the largest non-Christian religion is Arizona. The county with the largest percentage of Episcopalians is the Yukon-Koyukuk Census Area, Alaska. The Mormon Church in Madison County, Idaho, is larger than the county. (The county is “100.8%” Mormon.)