“Even so the tongue is a little member, and boasteth great things. Behold, how great a matter a little fire kindleth! And the tongue is a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body, and setteth on fire the course of nature; and it is set on fire of hell.
For every kind of beasts, and of birds, and of serpents, and of things in the sea, is tamed, and hath been tamed of mankind: but the tongue can no man tame; it is an unruly evil, full of deadly poison. Therewith bless we God, even the Father; and therewith curse we men, which are made after the similitude of God. Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.
Doth a fountain send forth at the same place sweet water and bitter? Can the fig tree, my brethren, bear olive berries? Either a vine, figs? So can no fountain both yield salt water and fresh.” James 3:5-12 (KJB)
Some verses which support the above:
“Death and life are in the power of the tongue: and they that love it shall eat the fruit thereof.” Proverbs 18:21
“But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire.” Matthew 5:22