I remember back in the times of the Constitution there was that blurb about separation of church and state.
That concept does not appear anywhere in the Constitution. It was a line in a letter written by Thomas Jefferson to the Danbury Baptist Church in defense of the First Amendment. The Supreme Court did not start redefining, revising and dismantling the Founder's conception of Freedom of Religion until the last half of the 20th century, and their decisions have been snowballing since then.