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. The tongue also is a fire, a world of evil among the parts of the body. It corrupts the whole person, sets the whole coarse of his life on fire, and is itself set on fire by hell.
(James 3:5-6)
Take a few minutes now to meditate on these verses.

Here the Bible is telling us that the direction of our whole life is set by our tongue. If you say positive things then you plant a positive seed and positive stuff is going to come your way.

Your tongue could be a fire and ruin people's lives or reputation, or it could be a blessing to people. You can't just say, "Oh, I felt like talking about this," or "No, I didn't feel like talking about this." Your tongue controls your destiny; it controls the direction of your whole life.

People say, "Well, I just can't help it if I have a bad attitude or if I'm having a bad day." Well, the Bible says you can help it, because the way you talk can change your attitude.

You say positive things, you say Scriptural things, and you set the pace for a Scriptural day. When you say negative things, then you set a curse for your day. The Bible says your tongue is a small thing, like the rudder of a ship.

Many of us can barely control our tongue in church on Sunday, much less the rest of our week. We wonder why so much of our life is falling apart, why so many bad things are happening to us. Well, one thing you need to check is your tongue.

There are some people you just love to be around because they say things to inspire, encourage, lift, and exhort you. You can't wait to be around them because you feel like you can do anything because of what they say to you. That's the kind of person you need to seek to be today. That's a mature believer, not looking for people to compliment you, but looking for people you can compliment.

Maybe you never realized how much power your tongue has in your life and the lives of those around you. You can walk into a room and totally set the pace for the day in a positive way, or you can set the pace for the day in a negative way.

You can do the same thing with your church group and with your family. It's your tongue, you can choose how you are going to use it. A mature believer says, "You know what, I'm going to use my tongue to point people toward God, toward hope, toward Jesus."

Source: Mature Christians Are Boring People...And Other Myths About Maturity In Christ by Ron Luce.
Excerpt permission granted by Teen Mania