In Psalm 5:9 David writes: “There is nothing reliable in what they say; their inward part is destruction itself. Their throat is an open grave; they flatter with their tongue.” This teaches us an important truth about where our words really come from:
— It starts on the inside. It says: “their inward part is destruction itself”.
SO as a result of that:
— “their throat is an open grave” and
— “they flatter with their tongue”
It is just as Jesus said, “The mouth speaks of that which fills the heart.” (Matt. 12:34) Do not say, of something that came out of your mouth, “I don’t know where that came from!” We DO know where it came from: it came from your heart! The mouth does not operate on its own; like the proverbial parrot, it only speaks that which it has heard: from the heart!
All of which goes to say that if someone has a problem with their words, it is not really a “mouth problem.” It is a heart problem, which can only be solved by a change from the inside out, through faith in Jesus Christ.