This document discusses controlling our tongue and how the things we say reveal the contents of our heart. It notes that controlling our tongue is difficult but important, as our words will be judged. It provides examples of harmful speech to avoid, such as filthiness, foolishness, lying, and complaining. Instead, we should speak words that are true, noble, beneficial, and build others up. How we use our tongue reveals our character and spiritual maturity. Our words also have power to determine our destiny, so we must be careful about what we say.