Mark Wilson via Getty Images President Donald Trump speaks while Vice President Mike Pence, Pastor Paula White, and Pastor Jack Graham listen during a National Day of Prayer event in the Rose Garden, at the White House, on May 4, 2017 in Washington, DC.

President Donald Trump celebrated the National Day of Prayer on Thursday by signing an executive order aimed at making churches and religious leaders even more powerful in the public arena.

Meanwhile, the American Humanist Association and other secular allies celebrated a day of reason to counter the annual day of prayer and affirm the importance of the separation of church and state.

“While the National Day of Prayer overtly excludes millions of nontheist Americans, the National Day of Reason embraces the values that bind us together as Americans, while upholding the wall separating church and state,” Roy Speckhardt, executive director of the American Humanist Association, said in a statement.

Congress passed a joint resolution in 1952 to establish the National Day of Prayer, and President Harry S. Truman signed it into law that year. Every president since then has signed a National Day of Prayer proclamation, and most ― excluding President Barack Obama ― have also held observances at the White House to honor the day.

Trump commemorated the day surrounded by clergy members as he signed an executive order in an attempt to circumvent the Johnson Amendment, which currently prevents churches and other tax-exempt religious groups from actively participating in politics.

Mark Wilson via Getty Images President Donald Trump is flanked by clergy members after signing an Executive Order on Promoting Free Speech and Religious Liberty, during a National Day of Prayer event in the Rose Harden at the White House, on May 4, 2017 in Washington, DC.

The Johnson Amendment is a 1954 law that restricts tax-exempt institutions, like churches, from actively campaigning for or against specific political candidates.

“Faith is deeply embedded into the history of our country, the spirit of our founding and the soul of our nation,” Trump told religious leaders and White House staff gathered for a National Day of Prayer celebration. “We will not allow people of faith to be targeted, bullied or silenced anymore.”

The Center for Inquiry, a secular nonprofit that also serves as home to the Richard Dawkins Foundation For Reason & Science, argued the Johnson Amendment provides necessary safeguards against the erosion of the separation of church and state.

“Despite the president’s claims today, religious leaders are already free to speak openly, and religious groups spend hundreds of millions of dollars per year lobbying, on all political issues,” Michael De Dora, director of government affairs for the Center for Inquiry, said in a statement. “To maintain their institutions’ tax exempt status, they are barred from partisan electioneering, a rule that is already woefully under-enforced.”

De Dora also noted that a majority of Americans are opposed to allowing churches and religious organizations to endorse political candidates while retaining their tax-exempt status.

In the context of Trump’s executive order, the National Day of Reason seemed more important than ever to secular advocates.

“On this National Day of Reason, reason must be protected even more as we watch science, facts, and basic truths be ignored by some of our elected leaders,” Speckhardt said.

The American Humanist Association has celebrated the National Day of Reason since 1953, according to the organization, and attempts have been made in recent years to get Congress to pass a resolution cementing the day.

At a time when people are disputing indisputable facts and axing scientific funding, celebrating reason and logic is more important than ever. Rep. Ted Lieu

Rep. Mike Honda (D-Calif.) and Delegate Eleanor Holmes Norton, a Democrat who represents the District of Columbia in the U.S. House of Representatives, introduced a resolution in 2016 to create a secular alternative to the National Day of Prayer.

This year, Rep. Ted Lieu (D-Calif.) introduced a similar resolution to recognize May 4, 2017 as the official National Day of Reason. “At a time when people are disputing indisputable facts and axing scientific funding, celebrating reason and logic is more important than ever,” Lieu said in an April statement.

In 2011, an appeals court overturned a lower court ruling that declared the National Day of Prayer to be unconstitutional. But the American Humanist Association and Washington Area Secular Humanists maintain that the National Day of Prayer violates the First Amendment of the Constitution by allowing the government use tax dollar-supported resources to celebrate religious ceremonies.

During Thursday’s gathering at The White House, the president told religious leaders: “We are giving our churches their voices back. We are giving them back in the highest form.” As part of the tax code, the Johnson Amendment could only be altered or repealed through an act of Congress. Trump seemed certain that his executive order would help American churches, though De Dora noted the order was likely a symbolic measure, albeit a frightening one at that.

“While this executive order won’t accomplish much in practical terms, it sends a signal that Trump is looking to reward his conservative evangelical base,” he said. “But this political payback is divisive and dangerous, blurring the line between church leadership and political operatives.”