Americans should be protected from interference with their faith as well as attempts by others to impose their beliefs. The institutions of government and church should be kept far apart, while the political realm is left open to arguments of all sorts, whether based on theism, humanism, or something else.
Walking home from the Capitol recently, I saw the words engraved above the portico of the Supreme Court: "Equal justice under law." They don't say "equal justice under law except for women." They don't say "equal justice as long as it's OK with your boss." And yet that is exactly what the court majority said in its ruling.