This morning at the White House I will join our nation’s leaders in one of the most sacred American traditions: Observing a day of prayer to repent and call unto God for his blessing, protection and guidance.

Praying publicly together as one people has been a part of our story since America was barely more than an idea. In 1775, faced with the prospect of imminent war, the Continental Congress called the 13 colonies to consecrate a day of “public humiliation, fasting and prayer.”

“We have appointed a Continental fast,” wrote John Adams to his wife, Abigail, on that first occasion. “Millions will be upon their knees at once before their great Creator, imploring His forgiveness and blessing; His smiles on American Council and arms.”

Since that day, American presidents have issued more than 140 calls to prayer. When the seas rise and darkness engulfs us, this is what we do as a people: We pray.

We prayed when a fierce Civil War exposed the threads of our fragile union and threatened to perpetuate the unconscionable enslavement of millions of innocent black men, women and children.

We prayed when our boys sailed unto the shores of Normandy on a June morning to face the might of Adolf Hitler’s Nazi forces.

We prayed when, on a September morning 16 years ago, terrorists flew two 767 jets into the World Trade Center and killed more than 2,600 Americans.

We prayed when in 2005 Hurricane Katrina tore a path of destruction and death from Florida to Louisiana; and when less than a year ago Hurricane Harvey devastated Texas.

Prayer is indeed woven into our DNA as a nation and people. But over the past few years we’ve tried to erase this undeniable fact from our history books. We’ve banned prayer from our schools and sneered at God’s face.

Lincoln’s self-examining warning, proclaimed more than 150 years ago, rings eerily true today:

“We have forgotten the gracious hand which preserved us in peace, and multiplied and enriched and strengthened us; and we have vainly imagined, in the deceitfulness of our hearts, that all these blessings were produced by some superior wisdom and virtue of our own. Intoxicated with unbroken success, we have become too self-sufficient to feel the necessity of redeeming and preserving grace, too proud to pray to the God that made us!”

More than being a moment to ask God’s blessing upon America, the National Day of Prayer is a somber reminder that we must never take things for granted. The freedoms we enjoy are not guaranteed by the power of our hand but by the grace of our Creator. We cannot assume we can enjoy the blessing of living in the most prosperous nation on Earth and write off God from our lives. As Lincoln concluded, “those nations only are blessed whose God is the Lord.”

If there has ever been a time to remember God, it’s now. We cannot only overcome the problems we are facing today on our own. This National Day of Prayer is an opportunity turn to that same providence that has guided us through many days and can guide us one again today.

• Jack Graham is the senior pastor of Prestonwood Baptist Church in Dallas.

Read more at How prayer is in America’s DNA.