"For out of the overflow of the heart the mouth speaks. The good man brings good things out of the good stored up in him, and the evil man brings evil out of the evil stored up in him. But I tell you that men will have to give an account on the day of judgment for every careless word they have spoken."
Matthew 12:34-36 (NIV)
When God speaks, eternal destinies are created. I believe that He made similar qualities in men and women. Each of us has the ability to speak. We differ from every other created thing on earth: God gave man the power of articulated words. What you say can also mould the lifetimes of others.
Every word you say is a seed. It will grow and produce fruit in the life of those who listen. It will either nourish or choke the life out of the person. "But they're just being too sensitive!" you may say. Our sensitivity is also our ability to hear and feel God. Shut that down and you will soon become jaded and cynical. If you are not sensitive, you are without sense!
At the root of words that tear down is envy. Some people cannot find joy in the joy of others. Unless it is happening to them, they want to rob others of the joy too.
Words are also contagious. How your parents spoke to you will generally be how you speak and also how your children will speak. A harsh word to someone may cause him or her to set in motion generations of destructive words. You may rob God of someone of great potential, all because you were threatened by his or her success.
The flip side is that you may be used by God to build someone into a mighty man or woman in life. You may even stop a suicide without realising it. You could see the power of generational curses lifted because you helped someone shake free of behavioural patterns with a positive word. So what's it going to be? Which word will you use? In a real way, God can use you powerfully through a positive word.