Photo by the White House

A terrible question stalks our land, even at this moment of promise and hope: Is there any principle left by which the United States can transcend the present bitterness and divisions over religion in public life and live up to the promise of the American experiment?

 Race was the older and, many thought, deeper of America's problems, but today's celebration of Martin Luther King Jr.'s birthday as well as Barack Obama's election shows how far we have come. Religion in public life is the next challenge.

Read the rest of Os Guiness' Commentary at USAToday.com