Where, specifically, is that concept of “separation of church and state” discussed in the founding documents?
I guess you don’t really understand why our government was formed in the first place. Also, why our founding fathers had no intention in founding a government like the one in England called the Church of England and its complete control of the government back then.
The founding documents establish the rights to freedom of religion, not government by religion.
Many of the founders (specifically John Adams) felt that our form of government would only be suitable for a population rooted in moral Christian principles...and no other.
Believing with you that religion is a matter which lies solely between man and his God, that he owes account to none other for his faith or his worship, that the legislative powers of government reach actions only, and not opinions, I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should "make no law respecting an establishment of religion, or prohibiting the free exercise thereof," thus building a wall of separation between church and State.
-Thomas Jefferson letter to To Messrs. Nehemiah Dodge and Others, A Committee of the Danbury Baptist Association in the State of Connecticut dated January 1, 1802