The State in free societies is to protect individuals, and groups from undue intrusion into private spheres. Some do not believe that separation of powers between State and religion is a good thing. I disagree.
Thomas Jefferson made a distinction between behavior, which should be ruled by law, and belief, which is not. Behavior impacts another's life, while belief is a personal matter. Some in our country would argue that one's beliefs cannot be fully held without legislating these beliefs, because they underwrite what defines morality. While this is true of some beliefs, even these convictions must be open to discussion, where the "free market" determines what transpires "under law". This is a just society that takes into account all members convictions, tries them in the public square, and votes on them in free elections. The result are our represetatives, who legislate our laws, but must be collegial to other opinions. It is what civil discourse is all about. There should be no personal attacks.
Some in the past, such as the Puritans of old, believed that theirs was a "commonwealth" under God, as revealed in Scripture. While this view had some virtues, it also held many vices. Their understanding of revelation was within a text, which is a human construct. It was the Church who decided what was to be contained in the canon. The Puritans, though, understood the text and Church in purely spiritual terms. It was a supernaturalism that called for an absolute obedience to the "rules" constructed by the Church or in the text. Theirs was not a free society of conscience, but one of enforcement of "law and order". While there is value to "law and order", there was much done in the name of "law and order" that subverted God's natural design in humankind. Dogma became the "law of the land", where Puritans held trials convicting those who did not adhere to their understanding or interpretaion of revelation (god). The same happens in Islamic countries under Shairia law. This is not justice.
Because humans are social animals and desire to belong to some group for identification, social collegiality, etc., I believe many people "conformed" to the "tradition" of Puritanism, and some even psychologically responded to "revivalistic sermons" to their felt need. Many others have suffered under the repression and oppression of such types of communities. Their understanding was a group identification that held many duties over their congregants. I find this disturbing.
While humans are social animals, there is something unhealthy about adult super dependence on others for identity. There are some cultures that thrive on group identification, but not so, in America. While there is a need for the child and young person to develop within social contexts and adults continue to change in their roles and understanding of themselves, individuation is necessary for one's personal "fulfillment" or maturity. This is not valued in some societies. While America's freedoms have allowed the fullness of individuation, it has also hindered our values of communal fellowship. This is because our way of life is so stressed and structured around work. Job opportunities call for moving across the country and a dissolution of family responsibilities.
The modern State, as we find it, still upholds the values of the individual conscience, while maintaining "law and order" so that individuals can live their lives in relative peace. Our Founding Fathers understood natural rights, as a creation order and structuring, where man would flourish most effieciently. The freedom to "be" and "become" are the values that America values and should be one of our ultimate value for it breeds a repsect for others in their individuation. And respect is about justice and value of another's life.