What was the genesis of God in America? Why take on this subject now?

You don't need to look any further that today's political/religious controversies -- over President Obama's personal faith, plans to build an Islamic center in lower Manhattan, or threats by a Florida pastor to burn copies of the Quran -- to sense the relevance of a series on how religious ideas and spiritual experience shaped America's public life.

However, the genesis of God in America did not occur in the crucible of today's headlines, but during a conference WGBH convened several years ago to discuss, with a room full of scholars and thinkers about religion, what direction public broadcasting could take to do more about the role of religious faith for an American audience.

The consensus at that conference was that America had a religious literacy problem. Several scholars define the problem this way: "Although many Americans are deeply religious, man can also be profoundly ignorant about religion -- about other faiths and sometimes even their own, as well as the religious history of the country."

Out of that conference five years ago came the idea for God in America -- to tell the often-neglected historical story of how religious ideas and spiritual experience shaped the public life of the country.

And undergirding the effort is a simple idea: In America, religion matters. In American history, it has always mattered, and we can't fully understand the American story without also understanding our religious history.

What made you decide to use dramatizations in the films?

Because the series was moving so far back into history -- nearly 400 years, when visual resources were often very sparse -- the team decided that inevitably we would have to dramatize some of the material to bring it to life and allow viewers access to both the human reality of events that propelled these historical figures, and how they thought and felt about what they were experiencing. The words spoken by the actors were all taken verbatim from transcripts, speeches and sermons, journals and other writings by the historical figures we portray.

Series director David Belton and producer/director Sarah Colt, who made the first four hours of the series that include dramatizations, found an intriguing style of dramatized monologues, rather than big scenes, that worked well for the series. They cast the roles and directed the actors very well to accomplish a subtle and sophisticated dramatization that enhances the humanity and the ideas, the intimacy and authenticity of the stories.

You tell 400 years of history in six hours. How did you decide what to include? Are there stories you wish you could have included?

Even in six hours, we could not be comprehensively inclusive in portraying this sprawling history and still do justice to the stories we were telling, so we concentrated on finding a series of emblematic stories that would expose the central dynamics of this history of how religion shaped America's public life. We were often drawn to "origin" stories, like the birth of evangelical Christianity, the roots of religious liberty and of social reform movements, the creation of a separate Catholic education system, the uses of religion in political conflicts like the revolution and the Civil War, the beginnings of the clash of religion and modernism, etc.

What surprised you the most in making the film?

Michael Sullivan: At the beginning of the project, as a relative newcomer to this history, much of it surprised me -- the early development of evangelical Christianity in America's history, the unexpected political alliance between Thomas Jefferson and the Baptists to forge the principles of religious liberty, the violent anti-Catholicism of the 1830s and '40s, Abraham's Lincoln's spiritual journey during the Civil War that changed his ideas about God and moved him to redefine the purposes of the war, the link between William Jennings Bryan's Christian beliefs and his political populism, and the journey of conservative evangelicals from shunning politics to embracing it. Overall, I was surprised with the depth of influence religious ideas and spiritual experience did, in fact, have on our political history.

Marilyn Mellowes: The history of religion and public life is full of surprises, but two really jumped out at me while I was doing the original research and development of the series. One was the way that religious dissidents -- Baptists, Catholics, Jews and atheists -- have pushed the meaning of religious freedom. The story of the Baptist alliance was Thomas Jefferson was completely new to me. I was also surprised by the impact of modernity -- how Darwinism and biblical criticism drove a wedge into American Protestantism, creating divisions between conservatives and liberals that we live with today.

The film traces how religious ideas and spiritual experiences have impacted America's social, political and cultural life. How do you assess the impact of nonbelievers?

The role of dissidents of all stripes, from those inside religious faiths and the impact of nonbelievers in the 20th century, is central to shaping our principles of religious liberty -- from Anne Hutchinson's defiance of Puritan authority and the resistance of George Whitefield and the Virginia Baptists to the established Anglican church, to Bishop John Hughes' battle with Protestants over Bible reading in the New York public schools, Rabbi Isaac Mayer Wise's reform of traditional Jewish religious practice, the new Biblical criticism of Presbyterian Charles Briggs, the struggle of both William Jennings Bryan and Clarence Darrow to define the role of science and religion; from the families that resisted religious instruction and prayer in the public schools that led to landmark Supreme Court decisions, to the leaders of the civil right movement and the religious right, all played strong roles in shaping Americans religious and political history.

Why does the series seem to focus on Protestant Christian stories?

In fact, the series contains several major historical chapters on Catholicism and Judaism, and also explores the rich diversity of the contemporary American religious marketplace -- with its millions of Muslims, Hindus, Buddhists and nonbelievers. But the historical story of God in America tracks back to the earliest days of the country, and for much of that history the central religious and political struggles were dominated by those of Protestant faiths. Even today, with all its religious diversity, the U.S. remains 75 percent Christian, with half of the population identifying themselves as Protestants.

Is religion's impact on American life growing or diminishing?

Surveys by the Pew Forum on Religion & Public Life have shown that America is one of the most religious countries in the developed world. Eighty-two percent of those surveyed report that religion is either "somewhat" or "very important" in their lives. Sixteen percent of those polled said they were "unaffiliated" with any particular faith, but a significant number in this group say that religion is important in their lives. The rise of the so-called "nones" suggests that a growing number of people define themselves as "spiritual but not religious."

Did making this film influence how you saw any of the summer's controversies, such as the Park 51 Mosque debate, the threats to burn the Quran, or Glenn Beck's "Restoring Honor" rally?

Michael Sullivan: After working on God in America, watching the current political/religious conflicts unfold made me feel both weary of the continuing battles and optimistic that we will eventually overcome them. We have been here before -- you can't watch the story of the Protestant-Catholic clashes of the 1840s in New York and not see how strongly they map onto the current conflict over the Islamic Center in Lower Manhattan, or [how] the 1960 concerns over John Kennedy's Catholicism map onto today's controversies about President Obama's personal faith. We have endured and survived religious controversies before, and the general trend lines of American life are to maintain a respect for religious liberty, and ultimately to become more inclusive and tolerant of the array of faiths that populate our country.

Marilyn Mellowes: The intersection of religion and political life has often been tumultuous. Knowing that we have managed to sort through repeated conflicts and controversies has made me more sanguine about our ability to resolve the issues that grab current headlines.