In U.S., Increasing Number Have No Religious Identity

"Americans have become increasingly less tied to formal religion in recent decades, with the percentage saying they do not have a specific religious identity growing from near zero in the 1950s to 16% this year and last.

[...]

An additional measure Gallup has tracked over time asks Americans if they believe that religion can answer all or most of today's problems, or if they believe religion is largely old-fashioned and out of date.

 

[...]

Bottom Line
Gallup surveys confirm a downward drift in religious identity among Americans, as well as a slight increase in the number of Americans who view religion as old-fashioned and out of date."

Gallup.com, May 21, 2010