April 18 (UPI) -- A Gallup poll released Thursday found that membership at religious institutions fell to an all-time low in 2018.
The survey found that the number of people who belong to a church, synagogue or mosque dropped to 50 percent last year, which is in line with similar trends including declining church attendance and an increase of Americans who do not identify a religious preference.
"The decline in church membership mostly reflects the fact that fewer Americans than in the past now have any religious affiliation," Gallup said. "However, even those who do identify with a particular religion are less likely to belong to a church or other pace of worship than in the past."
The number of people who reported having no religious affiliation increased from 8 percent between 1998 and 2000 to 19 percent between 2016 and 2018.
During the same periods, the number of people who say they have no religious affiliation but are still members of a religious institution has declined from 10 percent to 7 percent.
However, 64 percent of U.S. adults with a religious preference said they belonged to a religious institution compared to 73 percent at the turn of the century.
Membership in religious institution has also decreased steadily with each generation, with 68 percent of people born in 1945 or before saying they belong to such an institution, versus 57 percent of Baby Boomers, 54 percent of people in Generation X and 42 percent of Millennials.
Church membership has decreased in varying degrees between Christian faiths, dropping 13 percent among Catholics and 6 percent among Protestants.
"These trends are not just numbers but play out in the reality that thousands of U.S. churches are closing each year," Gallup said. "Religious Americans in the future will likely be faced with fewer options for places of worship and likely less convenient ones, which could accelerate the decline in membership even more."
The survey was conducted through telephone interviews with at least 2,000 U.S. adults, aged 18 and older in all 50 states and Washington, D.C., it was conducted with a 3 percent margin of error at the 95 percent confidence level.