Just as, 50 years ago, liberalism was the vital center of our politics, our religious landscape then was dominated by mainline Protestants and a Catholic Church becoming less Roman and more American every year. One of the most symbolic events occurred in 1958 when President Dwight D. Eisenhower laid the cornerstone for the new headquarters of the National Council of Churches here in New York City. Before a crowd of 30,000, Eisenhower quoted George Washington, who described religion as the firm foundation of the country's moral life.

That was the decade America put God on our paper money and in the Pledge of Allegiance. And though the churchly DNA often fostered racism, anti-Semitism, bigotry and Cold War dogmatism, many thought biblical religion, in its various incarnations, was the engine driving the American future.

But then, says Ross Douthat, American Christianity went off the rails -- and now threatens to take American society with it. Furthermore, the snake in the garden is not atheism, nor is secular humanism the worm in the apple. Our fall, he argues, is the work of heresy, as you see in the title of his latest book: Bad Religion: How We Became a Nation of Heretics.

Below is a clip from my conversation with Douthat that airs this weekend on Moyers & Company. Look for it on public television.