King David's fall into adultery and murder is a lesson in how sin happens and how we can respond to it. David's sin is preceded by idleness and sloth. Once fully aware of his sin, however, he appeals immediately to God's mercy. Our first response to sin should always be a radical trust in God's mercy and, when necessary, a prompt recourse to confession. In addition to trust in God's mercy, we should be resolute in our struggle against sinful habits.