In 2015, 53 percent of Americans said religion was very important in their lives, compared with 28 percent of Poles (which was the highest percentage for a European country). Just 21 percent of Brits and 14 percent of French people said the same thing [source: Pew Research].
So why has religion remained so popular in the U.S.? One theory is that since churches there aren't funded by the state, they have to be market-driven in order to survive — which may explain the popularity of megachurches tricked out like rock arenas, as well as prosperity gospel preachers like Joel Osteen who have a message that Americans (and others) like to hear. About 37 percent of Americans attend church weekly. By contrast, 80 percent of Norwegians are baptized into the state-funded Church of Norway but only 2 percent attend services weekly.
"When a state creates a relationship with a religion, religious leaders no longer have the same impetus to go out and get people excited," researcher Philip Schwadel told NPR in 2017. "They get money from the state through taxes, so they don't have to collect money from their congregants."
There are signs that religiosity is declining in the U.S. as well. From 2009 to 2015, the percentage of Americans who said their religious affiliation was "none" rose from 16 percent to 23 percent of the population — among millennials, it was 35 percent [source: Pew Research].