God looks at our hearts. Whether we like it or not, he searches our deepest, darkest, most depraved self. What the psalmist models at the end of 139 is concession, granting access to God to do his deep work. After expressing anger over evil in the world, he invites God to try his mind, test his heart, and lead him into a better way of life. We all need God's careful inspection of our interior life. He searches us in solitude. He cleanses us in confession. This sermon will highlight these disciplines as our response to God's incisive work.