A new study by the Pew Research Center suggests the religious landscape in America is shifting.
The share of U.S. adults who identify as Christian has dropped since 2007, from 78 percent to now just under 71 percent. At the same time, Americans who describe themselves as religiously unaffiliated grew from 16 percent to nearly 23 percent.
Pew's research information can be read here.
Research associate Dr. Jessica Martinez says there are two factors that explain the change. The first is what she calls general replacement: a young generation, replacing older generations, is not identifying with any religious affiliation, including Christianity.
A second factor is religious switching, when a person's religious affiliation differs from their childhood affiliation.
"Christianity loses more people through religious switching than they gain," Martinez observes, "whereas the religiously unaffiliated, on the other hand, gain more people through religious switching than any other group."
That's why one in five adults say they were raised in some religion and they no longer identify with a religion, she says.