Ephesians 4:29
Let no unwholesome talk come out of your mouths, but only such as is good for building others up according to the need of the moment, that it may impart grace to those who hear.
Matthew 12:35-37
The good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things.
Colossians 4:6
Let your speech always be full of grace, seasoned with salt, so that you may know how you ought to answer everyone.
Titus 1:10-11
For there are many rebellious men, empty talkers and deceivers, especially those of the circumcision.
James 3:6-9
And the tongue is a fire, a world of evil among the members of the body. The tongue corrupts our whole person, sets the whole course of our life on fire, and is itself set on fire by hell.
Romans 10:14-15
How then can they call on him in whom they have not believed? And how can they believe in him of whom they have not heard? And how can they hear without a preacher?
2 Corinthians 2:16
to the one a fragrance from death to death, to the other a fragrance from life to life. And who is sufficient for these things?
2 Corinthians 11:15
Therefore it is not surprising if his servants also disguise themselves as servants of righteousness. Their end will be according to their deeds.
2 Peter 2:18
For speaking out arrogant words of vanity, they entice by fleshly desires, by sensuality, those who barely escape from the ones who live in error.