3 When we put bits into the mouths of horses to make them obey us, we can turn the whole animal. 4 Or take ships as an example. Although they are so large and are driven by strong winds, they are steered by a very small rudder wherever the pilot wants to go. 5 Likewise, the tongue is a small part of the body, but it makes great boasts. Consider what a great forest is set on fire by a small spark. 6 The tongue also is a fire, a world of evil among the parts of the body. It corrupts the whole body, sets the whole course of one?s life on fire, and is itself set on fire by hell.
7 All kinds of animals, birds, reptiles and sea creatures are being tamed and have been tamed by mankind, 8 but no human being can tame the tongue. It is a restless evil, full of deadly poison.
9 With the tongue we praise our Lord and Father, and with it we curse human beings, who have been made in God?s likeness. 10 Out of the same mouth come praise and cursing. My brothers and sisters, this should not be. 11 Can both fresh water and salt water flow from the same spring? 12 My brothers and sisters, can a fig tree bear olives, or a grapevine bear figs? Neither can a salt spring produce fresh water.
James 3:3-12
15?Watch out for false prophets. They come to you in sheep?s clothing, but inwardly they are ferocious wolves. 16By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles? 17Likewise every good tree bears good fruit, but a bad tree bears bad fruit. 18A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. 19Every tree that does not bear good fruit is cut down and thrown into the fire. 20Thus, by their fruit you will recognize them.
21?Not everyone who says to me, ?Lord, Lord,? will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. 22Many will say to me on that day, ?Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?? 23Then I will tell them plainly, ?I never knew you. Away from me, you evildoers!?
Matthew 7: 15-23
19 We love because he first loved us. 20 Whoever claims to love God yet hates a brother or sister is a liar. For whoever does not love their brother and sister, whom they have seen, cannot love God, whom they have not seen. 21 And he has given us this command: Anyone who loves God must also love their brother and sister.
1 John 4: 19-29
All of these scriptures and many more warn Christians about gossiping and speaking badly of others. It is something that we should avoid completely.