Is America Religious? 20% Of US Has No Religion, While Still Mostly Christian

America is navigating away from religion. About one in five U.S. adults now answer "none" when asked for their religion, according to a Gallup survey released Friday.

In exact terms, 21 percent of Americans said they don't have a formal religious identity, which would have been previously unthinkable for the U.S. In the 1940s and 1950s only about 3 to 4 percent of Americans reported no religion. In 2008 even, that "none" identifiers group registered at just 15 percent, according to Gallup. Other surveys have shown that those who are religiously unaffiliated are likely to be younger, with nearly one-in-three Americans who are under 35 identifying with that group.

Gallup has tracked religious identification for eight years. During that time, the "none" identifiers have grown by six percent, while the number of Christians has decreased by six percent. Still, about 74 percent of U.S. adults identified as Christian. About 49 percent of Americans said they were Protestant/other Christian, 23 percent were Catholic and nearly 2 percent were Mormon, according Gallup. Other non-Christian religions accounted for 2.5 percent of U.S. adults, 2.1 percent identified as Jewish and 0.8 percent were Muslim.

Still, even across all religions, just 56 percent of U.S. adults said they were active members of church, synagogue or mosque.

"The most significant trend in Americans' religiosity in recent decades has been the growing shift away from formal or official religion," Gallup wrote. Seventy-two percent of Americans even told the surveying firm that religion was "losing its influence" in the country.

An ABC News poll on religion this year found somewhat different results, even if the big picture was the same. Eighty-three percent of Americans identified as Christian, while 13 percent had no religion, according to ABC News. Globally, it found 52 percent of the world was non-Christian, while about one-third of the world was Christian.