The Lord Jesus said, the mouth speaks what the heart is full of. An evil man brings evil things out of the evil stored in his heart.
A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart. For the mouth speaks what the heart is full of.
Luke 6:45
The most hateful of hearts uses the mouth to dehumanize the objects of his hatred. When hatred fills the heart, the mouth spews out defamation and slander. When a heart is full of anger, words are used as daggers to hurt and punish.
The aggrieved, resentful heart calls out for revenge and violence.
The person who is full of pride uses his mouth to boast about how great he (thinks) he is. With his lying lips, he exalts himself above all others. He shamelessly brags about his wealth, his ill-gotten gains.
Merely bragging about himself is not enough; an envious heart drives him to tear down the objects of his envy with derogatory words.
You will recognize bad people, not just by their words, but by the fruit of their actions. Bad fruit includes chaos and division, destroyed reputations and careers, and various forms of cruelty, such as the separation of immigrant parents from their children.
By their fruit you will recognize them. Do people pick grapes from thornbushes or figs from thistles? Likewise, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit.
Matthew 7:16-18
Why in the world can’t the American people recognize the heart of an evil man? Why did they pick such rotten fruit?
Innermost Being 