I called someone a functional atheist a few years back and they spent a lot of time trying to figure out what I meant. It was an off the cuff statement meant half in jest and half seriously and when I said it I had a vague notion of my intended meaning. Over the years I have thought about it quite a bit and recently I discovered some great resources that helped me define it.
The great promise of Immanuel, God with us, is made in the midst of a political intrigue and panic that can sound like the politics of today. In the historical hysterics and political nastiness Isaiah the Prophet tells of the people of God who will trust in God. The King and most of the people were so terrified of a confederation of Kingdoms coming against them that Isaiah says their hearts “shook as the trees of the forest shake in the wind” (Isaiah 7:2). The sign for them because of their political foolishness is a virgin giving birth to a son and calling him Immanuel. Isaiah’s command to the people of God is that they should not call a conspiracy what the rest of the people called a conspiracy or fear what they feared, and they should not be in dread. “The Lord of host, him you shall regard as holy. Let him be your fear, and let him be your dread”.
The marvelous promise of the coming of the Savior is set in the middle of “functional atheism”. God continually promises the political classes and the King that he will protect them and they continually “disbelieve” and act as if God is not in control. That is a functional atheist. Are you one? Do you live emotionally as if God had not saved you, then you are. If you respond to life in a way that makes God look helpless, weak, and worthless you are. If your first reaction to tough situations is panic rather than prayer, you might be. (This comes from a marvelous section of a book on preaching called “Isaiah: God Saves Sinners”, by Raymond Ortland Jr. Crossways Books, Wheaton IL 2005)
You may go to church on occasion, have your children baptized, get married by benefit of clergy (often in that order), and still live as if God is not God. Functional atheism is all around us. We will think about how God could be our “dread” tomorrow.