Though [Thomas] Jefferson explained that the First Amendment "built a wall of separation between church and state," he still publicly practiced his religion.
In fact, historical experts explained how Jefferson attended public church services every Sunday in the Capitol building and permitted church services to be held in executive office buildings.
"On a Sunday in Washington in … the 1810s, you would have had services going on in all branches of government," Library of Congress historian James Hutson said. "You could actually say that the state became the church on Sunday in Washington and so, some of these arguments we’re having today about religion in the public square are certainly not grounded in the historical record."
https://www.foxnews.com/media/one-nation-under-god-fox-nation accessed 9-30-2021