The idea of "separation of church and state" is credited to Thomas Jefferson. He articulated this principle in a letter to the Danbury Baptists in 1802, emphasizing the necessity of maintaining a clear divide between religious institutions and governmental powers. This concept aims to protect the free exercise of religion while ensuring that the state remains neutral in religious matters. Jefferson’s vision has significantly influenced the development of religious freedom policies in the United States and remains a critical element of modern democratic governance.