Whenever I said something naughty as a child, my mother washed out my mouth with soap. It was not my mouth that needed cleansing, though; it was my heart! You see, your tongue speaks what is already 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, but it also reveals to me that my heart is unclean.
If I gossip, tell off-color 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 haven’t dealt with, or I wouldn’t be saying such things. Why do I go on gossiping? Why do I utter mean, careless words? What unsanctified strongholds still exist in my heart?”
Jesus gave 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, NKJV). Jesus was saying, “If you are careless with your tongue—quarreling, complaining, murmuring, tattling—you have a serious heart problem, and it goes very deep.”
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 sin in my heart. Dig deep into my heart and pluck out the roots of bitterness, pride, jealousy or whatever it is.” God wants to help you deal with every sin that pulls you into its grip. All you have to do is ask him; he will root it out and heal you completely.