I once heard a story of a man who sought to commit suicide. He believed humanity in general was cruel and self interested, and getting worse by the minute. From here, he made an agreement with himself. If just one person greeted him on the way to the bridge he intended to throw himself from, he would not jump. Just one word saved this man's life: Hi.
You see the power of words. Just one word can save a life. Similarly, one word can end it. Bully someone enough, even if it's just a horrible name, you can crush their spirit to breaking point. As they taught me in high school, "sticks and stones may break my bones, but words can break my heart".
If words are so powerful, we should carry them like the weapons they are. Only a complete moron waves a gun around with his finger on the trigger. A wise man will exercise large amounts of discipline over such a potentially destructive force. With a gun, if you pull the trigger, you have to mean it. My brethren, your gob is a gun. So is a pen. Or a keyboard. Be very careful with what you say, write, or type. If you do not mean what you say, do not even risk having it brought up on Judgement Day. If you would not be 100% willing to justify your words in front of God, shut up.