LANCASTER, Pa. -- America just marked its 239th Independence Day, the birth of what many consider the greatest nation on earth. But after all these years of celebrating, Americans may soon be mourning its downfall. That's the conclusion of researcher George Barna and historian David Barton in their book U-Turn: Restoring America to the Strength of Its Roots. ***** Faith is losing its foothold in the land. "The proportion of unchurched people has risen from 28 percent to 48 percent in six years," Barna shared. "The fastest growing faith group in America is atheists and agnostics."