What are we writing on the ground?

Had a quick chat with my sister this morning and show had filled me in on a service that she is holding tomorrow at her church. An individual there will be bringing a powerful testimony which will in turn go up against the mindsets of many. She asked that my wife and I keep the event in prayer, which of course we will. So this brought a question up in me, what are we writing on the ground? As Jesus stood in the gap for the woman who was caught in adultery; the bible says that he wrote on the ground. And what came after was a simple statement that caused the crowd to turn and walk away from their initial purpose of stoning that woman. What are we writing on the ground?