For he that will love life, and see good days, let him refrain his tongue from evil, and his lips that they speak no guile: Let him eschew evil, and do good; let him seek peace, and ensue it. (1 Peter 3:10-11 KJV)
It goes without saying, that life is far more pleasant for everyone when we all seek peace with one another and avoid speaking evil of others.
I remember being a guest at someone's house one day and there was a picture of a gal on the fridge. I don't remember exactly what was said but a friend of the person whose house I was at saw the picture and proceeded to verbally shred the person in the photo. The person whose house I was at chimed right in on the verbal carnage. I was left standing there speechless and awkward. None of the women involved are Christians, but it did illustrate to me the opposite of refraining my lips from evil and the opposite of speaking no guile.
When you speak evil of others, it is apt to come back around to the one it is spoken of. This is not peace seeking. Rather it has the potential for exploding in your face. I need to take this scripture to heart and practice it.