Immeasurable harm is done by lies, slander, gossip, and abusive speech.
If you want to measure the value of your religion, examine your speech. If any one thinks himself to be religious, and yet does not bridle his tongue but deceives his own heart, this man's religion is worthless. And I say to you, that every careless word that men shall speak, they shall render account for it in the day of judgment. For by your words you shall be justified, and by your words you shall be condemned. For the mouth speaks out of that which fills the heart.