The Christian church has been a cornerstone of American life for centuries, but much has changed in the last 30 years. Americans are attending church less, and more people are experiencing and practicing their faith outside of its four walls. Millennials in particular are coming of age at a time of great skepticism and cynicism toward institutions—particularly the church. Add to this the broader secularizing trend in American culture, and a growing antagonism toward faith claims, and these are uncertain times for the U.S. church. Based on a large pool of data collected over the course of this year, Barna conducted an analysis on the state of the church, looking closely at affiliation, attendance and practice to determine the overall health of Christ’s Body in America.

Most Americans Identify as Christian Debates continue to rage over whether the United States is a “Christian” nation. Some believe the Constitution gives special treatment or preference to Christianity, but others make their claims based on sheer numbers—and they have a point: Most people in this country identify as Christian. Almost three-quarters of Americans (73%) say they are a Christian, while only one-fifth (20%) claim no faith at all (that includes atheists and agnostics). A fraction (6%) identify with faiths like Islam, Buddhism, Judaism or Hinduism, and 1 percent are unsure. Not only do most Americans identify as Christian, but a similar percentage (73%) also agree that religious faith is very important in their life (52% strongly agree + 21% somewhat agree).

Attending Church Is a Good Indicator of Faith Practice Even though a majority of Americans identify as Christian and say religious faith is very important in their life, these huge proportions belie the much smaller number of Americans who regularly practice their faith. When a variable like church attendance is added to the mix, a majority becomes the minority. When a self-identified Christian attends a religious service at least once a month and says their faith is very important in their life, Barna considers that person a “practicing Christian.” After applying this triangulation of affiliation, self-identification and practice, the numbers drop to around one in three U.S. adults (31%) who fall under this classification. Barna researchers argue this represents a more accurate picture of Christian faith in America, one that reflects the reality of a secularizing nation.

Another way Barna measures religious decline is through the “post-Christian” metric. If an individual meets 60 percent or more of a set of factors, which includes things like disbelief in God or identifying as atheist or agnostic, and they do not participate in practices such as Bible reading, prayer and church attendance (full description below), they are considered post-Christian. Based on this metric, almost half of all American adults (48%) are post-Christian.