It’s like clockwork — every Christmas there’s controversy about religious displays. This year they took down Christmas trees at the Seattle International Airport due to a complaint. A few days later they put them back up, but why was there a problem to begin with?

As a former professor of history, I can tell you this is not what the Founding Fathers envisioned. Just how did they view religion in the public square, and why have things changed so much since?

I investigate this in my tour of our capital’s monuments in the FOX News special One Nation Under God: Religion and History in Washington, D.C.

Along the way, we learn lots of fascinating facts. For instance, did you know the Washington Memorial was left half-completed for 30 years while its supporters scrambled to find more money?

Or that the Lincoln Memorial was near impossible to build, because the area they chose for it was a swamp?

Or that, following his wishes, the Franklin Delano Roosevelt Memorial did not depict the man in a wheelchair — until activists complained?

These and many other things in our special (including fun quiz questions to keep you on your toes) help bring the past alive.

But this isn’t just a history lesson — it’s as relevant to us as what happened in Seattle. We can see in these memorials how important faith was to our founders. Later leaders too, such as Lincoln and FDR, relied upon faith in some of the darkest moments in our history.

Yet, while the older monuments reflect this spiritual side, the newest ones obscure or ignore it.

Supreme Court decisions have helped create an America, as shown by the Seattle dispute, that’s suspicious of religion in public. And yet, as we’ll see, the Supreme Court building is itself full of religious imagery, including several nods to Moses and the Ten Commandments.

Historically, our elected officials have often led us in religious observance. Today, they’re more likely to be removing religion from public life, regardless of what the people want. It’s through understanding the past that we can reclaim what’s best in our culture.

So tune in for One Nation Under God: Religion and History in Washington, D.C. on Saturday at 9pm / Midnight ET and on Sunday at 4pm ET. I think you’ll find it informative, colorful and entertaining.

Former Speaker of the House Newt Gingrich is a political contributor for the FOX News Channel. You can read his complete bio here.

Newt Gingrich, a Republican, was speaker of the United States House of Representatives from 1995 to 1999. He is the author of the new novel “Duplicity" and co-author, with his wife Callista Gingrich, of "Rediscovering God in America: Reflections on the Role of Faith in Our Nation's History and Future" (Center Street, May 17, 2016).