In my own reading it seemed timely to me that I came upon a section in an apologetic book which dealt with the separation of church and state as commonly (mis)understood today. The author is Dr. John Frame, retired professor of systematic theology and philosophy at Reformed Theological Seminary, Orlando. Here are a few highlights...
The Christian, as opposed to the secularist, comes to realize we are accountable to a law higher than, and outside of, ourselves. Namely, "the source of morality is greater than our family, our clan, even our church. Greater than our present loyalty, but not greater than loyalty itself. Morality is grounded in a higher loyalty, and a higher love."
Christians do not abandon the use of reason, but rather they reject purely autonomous reason: "Only Christianity, abandoning autonomy for trust in God’s revelation, presents a suitable account of both the powers and limitations of reason, neither deifying nor denying our rational faculty."
On the separation of church and state: "This clause does not forbid religious expression in government, or government support of such expression. It does not even forbid established churches within the new nation, except at the federal level. At the time, there were established churches in the states. Part of the purpose of this amendment was to keep the federal government from competing with those state churches or interfering with them. In broadening this provision, courts have cited Jefferson’s language of the 'wall of separation' between church and state. However, this phrase appears in Jefferson’s writings, not in any official government document. The phrase comes from Jefferson’s 1802 letter to the Danbury Baptist Association, replying to their letter of 1801. The letter assures them that their opinions will not be scrutinized by the federal government. So, the 'wall of separation' is to protect the church from the state, not the other way around. So, although courts have interpreted it differently, there is nothing in the First Amendment that requires government officials to be entirely secular in the conduct of their duties."
On the free exercise of religion. Frame writes, "...the amendment protects the 'free exercise' of religion. Nothing in the Constitution gives anyone the right to 'freedom from religion,' the right not to be offended by religious expression. But in recent years the federal government has become more and more intrusive into the practice of religious believers."
Freedom of religion means more than freedom to worship: "...that certainly was not the meaning of 'free exercise' when the Constitution was written. ...religion is not limited to what we do in the church building. It is emphatically what we do after the service is ended. Our Puritan fathers understood this, and certainly the writers of the Constitution. That is, indeed, the case for all religions, not just Christianity. Every preacher tells his flock that they should practice their faith wherever they go, that they should not limit it to their time in public worship."
-- Excerpts are taken from Christianity Considered: A Guide for Skeptics and Seekers (Lexham Press, 2018), by John M. Frame.