The Bible talks about the power of the tongue. God’s word is clear that as Christians, we’re to be mindful about what comes out of our mouths. It says that we have the tendency to bless one minute and to curse the next. This means we have to forego our flesh to enact the Spirit of God within us.
The inspired Word of God reminds us that words either build or tear down. The following are scriptures that show God’s heart in this matter. (Taken from the ESV)
Whoever keeps his mouth and his tongue keeps himself out of trouble.
Let no corrupting talk come out of your mouths, but only such as is good for building up, as fits the occasion, that it may give grace to those who hear.
There is one whose rash words are like sword thrusts, but the tongue of the wise brings healing.
Keep your tongue from evil and your lips from speaking deceit.
For we all stumble in many ways. And if anyone does not stumble in what he says, he is a perfect man, able also to bridle his whole body. If we put bits into the mouths of horses so that they obey us, we guide their whole bodies as well. Look at the ships also: though they are so large and are driven by strong winds, they are guided by a very small rudder wherever the will of the pilot directs. So also the tongue is a small member, yet it boasts of great things. How great a forest is set ablaze by such a small fire! And the tongue is a fire, a world of unrighteousness. The tongue is set among our members, staining the whole body, setting on fire the entire course of life, and set on fire by hell. ...
A soft answer turns away wrath, but a harsh word stirs up anger.
1 Peter 3:10
For “Whoever desires to love life and see good days, let him keep his tongue from evil and his lips from speaking deceit;
If anyone thinks he is religious and does not bridle his tongue but deceives his heart, this person's religion is worthless.
Not many of you should become teachers, my brothers, for you know that we who teach will be judged with greater strictness. For we all stumble in many ways. And if anyone does not stumble in what he says, he is a perfect man, able also to bridle his whole body. If we put bits into the mouths of horses so that they obey us, we guide their whole bodies as well. Look at the ships also: though they are so large and are driven by strong winds, they are guided by a very small rudder wherever the will of the pilot directs. So also the tongue is a small member, yet it boasts of great things. How great a forest is set ablaze by such a small fire! ...
Even a fool who keeps silent is considered wise; when he closes his lips, he is deemed intelligent.
A gentle tongue is a tree of life, but perverseness in it breaks the spirit.
Death and life are in the power of the tongue, and those who love it will eat its fruits.
From the same mouth come blessing and cursing. My brothers, these things ought not to be so.
“Either make the tree good and its fruit good, or make the tree bad and its fruit bad, for the tree is known by its fruit. You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks. The good person out of his good treasure brings forth good, and the evil person out of his evil treasure brings forth evil. I tell you, on the day of judgment people will give account for every careless word they speak, for by your words you will be justified, and by your words you will be condemned.”
Does a spring pour forth from the same opening both fresh and salt water?
When words are many, transgression is not lacking, but whoever restrains his lips is prudent.
For lack of wood the fire goes out, and where there is no whisperer, quarreling ceases.
To the choirmaster: to Jeduthun. A Psalm of David. I said, “I will guard my ways, that I may not sin with my tongue; I will guard my mouth with a muzzle, so long as the wicked are in my presence.”
The mouth of the righteous utters wisdom, and his tongue speaks justice.
Whoever covers an offense seeks love, but he who repeats a matter separates close friends.