The Founding Fathers sought to forbid the establishment of a state church, but they were positively not advocates of irreligion. It seems odd that today's noisier elements on the Left seem to fear the establishment of a state church, which has not been a threat for a couple of hundred years. Some people can lead moral lives without any sort of church, but they are the minority. Most people need sanction in order to lead moral lives. The state describes what is a crime. The church describes what is a sin, and a given act may be either or both, with or without fear of punishment, here or hereafter. See what happens to the post-moderns who attempt to set up a society without rules, either civic or religious! A man's behavior is more effectively controlled by his conscience than by the law, because while he may be able to avoid legal punishment he can never escape his conscience. Of course, he must have a conscience, as the current counter-culture creeps apparently do not.
From his Commentaries, Volume 11.