Formal religious affiliation in the United States falls below the majority for the first time since Gallup started polling

Gallup Inc. chart; click the image to enlarge it

The share of Americans who consider themselves members of a church, synagogue or mosque has dropped below 50 percent, according to a Gallup poll released Monday. That hasn't happened since Gallup started asked the question in 1937, when membership was 73%, Sarah Pulliam Bailey reports for The Washington Post: "In recent years, research data has shown a seismic shift in the U.S. population away from religious institutions and toward general disaffiliation, a trend that analysts say could have major implications for politics, business and how Americans group themselves. In 2020, 47% of Americans said they belonged to a church, synagogue or mosque. The polling firm also found that the number of people who said religion was very important to them has fallen to 48%, a new low point in the polling since 2000."

Other findings from the poll and other research:

• The decline in religious membership is primarily due to the increasing number of Americans who say they do not identify with any organized faith. The percentage of Americans who say that grew from 8% in 1998-2000 to 13% in 2008-2010 and 21% over the past three years.
• Church membership is strongly correlated with age; 66% of people born before 1946 (known as traditionalists) belong to a church, compared with 58% of Baby Boomers, 50% of Generation X and 36% of Millennials. The limited data on adult members of Generation Z suggests similar figures to that of the Millennials.
• Faith, or at least the organized version of it, has been lost. Since 2000, the percentage of traditionalists, Baby Boomers, and Gen Xers with no affiliation has nearly doubled; from 4% to 7% for traditionalists, from 7% to 13% for Baby Boomers, and from 11% to 20% for GenXers. The percentage of Millennials with no religious affiliation is 31%, up from 22% a decade ago, and 33% of Generation Z that has reached adulthood has no religious preference.
• Each generation has seen a decline in church membership among those who have a specific religious affiliation. For traditionalists, Baby Boomers and Gen X those declines have ranged between 6 and 8 percentage points over the past 20 years.
• Over the past 10 years, the share of religious Millennials who are church members has declined from 63% to 50%.
• Despite all that, Americans are more likely than people in other countries to say their religious faith has become stronger during the pandemic, according to the Pew Research Center.