James in his Epistle talks about Restraining the Tongue. He's absolutely right. The tongue is to be restrained and tamed. I have no doubt that what comes out of the mouth has started world wars in the past, broken up our families, and is still causing unhappiness every moment to this day. Sometimes we just express our feelings and what comes out is misconstrued as our intention to hurt someone. Sometimes we just make one comment and someone takes it personally and starts venting his or her own feelings. Often what's said is easily considered as a "complaint" by others. I suppose anything said that's not very positive is fair game for any listener. I almost feel that when I express myself, I am navigating through a mine field.
I believe that what we should do is to say less and speak only if we have something loving and positive in mind. If there are negative feelings, go to Jesus and tell him all about them. I found very few people will truly listen to you objectively and try to see things from your point of view, but thank God that we have our Lord who loves us warts and all, understand us perfectly, and is always sympathetic. Even his scolding is sweeter than praises from other humans, because when he chides us, it's for our own good.