Our founding fathers clearly wanted freedom of religion, but wanted our Nation governed in a secular manner. As I have stated before, 'We are a Nation of Christians, but we are not a Christian Nation".
Then why did they not insist that the states who had explicitly Christian state constitutions at that time amend them before they could join the United States?
There were many things they failed to do to live up to the greatness embedded in the Constitution, including slavery, child labor, women's rights. But time has resolved many of those shortcomings. Every one of those so-called Christian state constitutions, and there were several, violated the US Constitution with their explicit religious tests. I don't make excuses for the failure of the federal government to protect the rights of its citizens. But it has learned over the years that a government's first duty is to protect the rights of all of its citizens, not just good Christian white male landowners.