right. so where is that phrase in any of the constitution, the bill of rights, or any federal or state law?
It is not there. The reason it is not there is simple. Unlike England, the founding fathers did not establish a State church. They, and many of their fellows, suffered discrimination and even persecution as a result of not adhering to the authority of the Church of England. Because of that historical experience, the founding fathers established a nation where Christians were free to practice the denomination of their own choosing, and according to their own conscience. Until the Godless "Liberals" seized control of academia, that was common knowledge.