David Wilkerson emphasizes that the true source of our words lies in our hearts, highlighting that careless speech reflects an unclean heart. He urges believers to take seriously Jesus' teaching on taming the tongue, recognizing that gossip and harsh words indicate deeper heart issues. Wilkerson challenges us to examine our hearts for unresolved bitterness, jealousy, or pride that may lead to harmful speech. He reminds us that God desires to cleanse our hearts and remove the hidden poison that affects our words and actions. Ultimately, the sermon calls for a deep introspection and a plea for God's healing touch in our lives.

Whenever I said something naughty as a child, my mother washed out my mouth with soap. But it was not my mouth that needed cleansing, it was my heart! You see, your tongue speaks only what is in your heart. Those are the very words of our Lord Jesus Christ and He says that loose, careless, evil talk can come only from an unclean heart. As believers, we have not taken seriously what our Lord said about taming our tongues. He has made it a heart issue! Not only does my careless tongue discount all my spirituality, it also makes me face the fact that my heart is unclean. If I gossip, tell dirty jokes, run down other people, raise my voice and scream at my family, I must ask myself: “What unclean, filthy stuff is still stored up in me that I could speak this way?” I must examine my heart and ask, “Where does this come from? There must be something I have not dealt with or I wouldn’t be saying such things. Why do I go on gossiping? Why do I utter such mean, careless words? What unsanctified strongholds still hold my heart?” Jesus gives this matter serious weight: “How can you, being evil, speak good things? For out of the abundance of the heart the mouth speaks. A good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things” (Matthew 12:34-35). Jesus is saying, “If you are careless with your tongue—quarreling, complaining, murmuring, tattling—you have a serious heart problem! Your heart is not right with God, and it goes very deep. There is an evil treasure stored up in you, just as a snake has bags of poison stored behind his jaw. If deadly poison is coming out of you, it is because the bag has not been drained!” Whenever I allow something unclean to come out of my lips, I must stop and say to the Lord, “Master, there must still be a root of jealousy, envy or lust in my heart. Dig deep into my heart and pluck out the roots of bitterness, pride or whatever it is!” God wants to get at that evil in your heart, that bag of poison hidden inside of you! He wants to root it out and heal you completely.