A large majority (81%) of Americans say they believe in God, based on the poll conducted May 2-22, but that number has dipped 6 points from a consistent 87% from 2013 to 2017.
Over 90% of Americans said they believed in God from 1944 to 2011, the number stabilizing at a high of 98% from 1944 through the 1960s.
About 17% of American adults told Gallup that they do not believe in God, while the remaining 2% said they were unsure.
The Gallup Values and Beliefs poll found that the decrease in theism has been driven by young adults and those on the political left. Both groups’ belief in God has dropped by 10% or more compared to the 2013-2017 average for their demographics.
These groups are also those least likely to say they believe in God in comparison to other demographics.
Liberals (62%), young adults (68%) and Democrats (72%) gave significantly lower rates of belief in God, while conservatives (94%) and Republicans (92%) gave the highest.
The least change in belief has occurred among conservatives and married adults.
The Gallup poll marks a notable change in belief in God, although a sizable majority of Americans still say they have faith.
However, recent polls show that while high rates of theism remain with only a modest decline, traditional religious structures are declining faster, according to Gallup.
Gallup has found that Americans are much less likely to attend church, become members of a church or rate themselves as confident in organized religion than to simply believe in God’s existence.