"Our form of government has no sense unless it is founded in a deeply felt religious faith, and I don't care what it is. Of course, it is the Judeo-Christian concept, but it must be a religion with all men being created equal." President Dwight Eisenhower, December 22, 1952. Of course Eisenhower didn't mean it should be the law. Actually, up until his time, there was a lot of anti-Catholic and anti-Jewish sentiment in the US. A slim majority of Americans still thought it was wrong to be Jewish in 1945. Eisenhower said, be religious, but it's your choice which. The SCOTUS later said atheism is protected too. But Justices Scalia and Thomas disagreed, Scalia at first. You can chose, but chose at least one. For them, that would be Catholicism. But they meant Jainism or Satanism would do too.
That's what Ike said. What did he mean? Ike was way before my time, but from what I've read about him, he was good for the country at the time (i.e., 1950s). He had good values and stood for principles that transcended personal power and political gain. Like many, he probably was convinced that this came from religion, broadly defined. Many of the founders who designed our form of government were Deists, who did not give us an established church but instead provided that "Congress shall make no law respecting an establishment of religion or prohibiting the free exercise thereof." The "Christian Nation". The Declaration of Independence, written by a man who believed in "separation of church and state", provided that our rights come from a “Creator” and “Nature’s God” — but were non-specific about His/Her identity. I've known enough principled atheists (and unprincipled theists) to believe that commitment to a religion isn't necessary for virtue, but that commitment to the public good, morality, and principle above personal advantage are essential.