From Dave Black Online:

Jesus writes in the sand. Why? To show that He remains above the angry mood of the crowd. By remaining in total control of Himself, He broke the momentum of the moment. Is Jesus writing in the sand of your life? Or in your family? Or in your denomination? Yes, Jesus can even speak to a denomination if we will listen. Composure in the midst of crisis. Serenity in the midst of silliness. Let Him write, Baptists, let Him write, Methodists, let Him write!