Eph. 4:29 states,
Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.
Additionally, Col. 4:6 says
Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone
Those who consider themselves religious and yet do not keep a tight rein on their tongues deceive themselves, and their religion is worthless.James 1:26