Pew study on religion, and here is a brief summary with a graph:
What does this mean for parents? for churches? for pastors?
Some Evidence of Decline in Religious Commitment in the U.S. Public
The continued growth of the religiously unaffiliated is one of several indicators suggesting that the U.S. public gradually may be growing less religious. To be sure, the United States remains a highly religious country – particularly by comparison with other advanced industrial democracies – and some measures of religious commitment in America have held remarkably steady over the years. The number of Americans who currently say religion is very important in their lives (58%), for instance, is little changed since 2007 (61%) and is far higher than in Britain (17%), France (13%), Germany (21%) or Spain (22%).8 And over the longer term, Pew Research surveys find no change in the percentage of Americans who say that prayer is an important part of their daily life; it is 76% in 2012, the same as it was 25 years ago, in 1987.
But on some other key measures, there is evidence of a gradual decline in religious commitment. In 2003, for instance, 25% of U.S. adults indicated they seldom or never attend religious services. By 2012, that number had ticked up 4 points, to 29%.