What you put in your mouth goes out as waste. What comes out of your mouth comes from within you. Your mouth expresses what you have inside your mind/spirit. When all you do is express negativity, it's because you are a negative. Pray for the negative. See to it what you can do to turn the darkness into light.
Matthew 7:15-20
You Will Know Them by Their Fruits
15 “Beware of false prophets, who come to you in sheep’s clothing, but inwardly they are ravenous wolves.
16 You will know them by their fruits. Do men gather grapes from thornbushes or figs from thistles?
17 Even so, every good tree bears good fruit, but a bad tree bears bad fruit.
18 A good tree cannot bear bad fruit, nor can a bad tree bear good fruit.
19 Every tree that does not bear good fruit is cut down and thrown into the fire.
20 Therefore by their fruits you will know them.