So people whose views have been religiously formed have to learn, and many have learned, to express them in ways that make sense to irreligious or differently religious fellow citizens. Talk of God’s will and appeals to revealed truth are best left out of political discourse. But this, again, isn’t an absolutist position in our secular state. Martin Luther King Jr.’s’s invocation of the biblical line that describes all human beings as “created in the image of God” seemed to work well in our democratic politics–I have never heard committed atheists objecting. But when I repeat it, I also extend it: “All human beings are created in the image of God, whether or not God exists.” I suppose that is a universalizing, if illogical, move, but the original version has proven to be perfectly acceptable. It represents another compromise with or even acceptance of a widely shared–and, for people on the liberal left, politically useful–religious idea. But other religious ideas, the value of life, for example, or care for the poor, have also been successfully invoked in American political discourse.
Secular talk with religious phrases probably works better than secular talk by itself–at least in America. The cultural requirements of separationism don’t prohibit religious references in our political discourse so long as religious or any other minorities are not condemned or excluded. “Creation in the image” excludes no one. Nor does the American wall exclude the compromises that I have already mentioned, like Memorial Day religiosity and Sunday observance. The wall isn’t an impenetrable barrier; it doesn’t prevent occasional crossings. Perhaps we should call this liberal separationism, where the adjective “liberal” works against any sort of absolutism and describes a society as open as it should be. Against any illiberal closure we look for a constitutional remedy.
Michael Walzer, The Struggle for a Decent Politics: On “Liberal” As An Adjective, 136-137.