David took a census of fighting men in Israel, which angered God. As a result of David's sin of pride and failing to follow ritual law, God caused a plague to strike Israel that killed over 70,000 people. The sermon argues that while we may not know the full nature of others' sins, our own sins can have far-reaching negative consequences for many beyond just ourselves, as was the case with David's census. Therefore, we must have a penitent heart like David and consider how our choices could impact others.