The verses are foundational in answering the question, "What wrong with me?" In this passage Jesus teaches that, sin isn't the result of our environment, but of the evil in our own hearts. It's not what's on the outside that makes us evil; it's what comes from inside our hearts that showcases the evil within. | Outline: [I] Explanation from Jesus about Defilement, vs. 14-23 [a] Sin is not the result of our environment, but of the evil in our own heart [II] What "Heart" Means in the Bible [a] It's the seat of your emotion, motivation, will, thought, desire, and the causal center of your personhood [III] What's Wrong with My Heart [a] It's ruined by self-centeredness [b] It has the seeds of all evil in it [c] It's what makes me unclean before God