Except for the book of Proverbs, the book of James has more to say about the mouth and the little muscle called the tongue than any other book in the Bible. James tells us in Chapter 3 that:

(1)  The tongue may be very small, but it is powerful. It has the power to control our lives.
(vs. 3) "When we put bits into the moths of horses to make them obey us, we can turn the whole animal."
(vs. 4) "Or take ships as an example. Although they are so large and are driven by strong winds, they are steered by a very small rudder wherever the pilot wants to go."

James is telling us that our tongues act like a bit and rudder to direct our lives. Both  the bit and rudder, though very small, controls and directs the horse and ship. Our tongue can control and change the very course of our lives by the words it speaks.

(2)  The tongue may be small, but it is dangerous.
(vs. 5 -6) "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 course of his life on fire, and is itself set on fire by itself."

Great forest fires are destroyed by the careless toss of a match or cigarette. Careless words from our mouths can destroy in the same way. The tongue can ignite a spark that can set a whole forest of lives and relationships on fire.

(vs. 7-8) "All kinds of animals, birds, reptiles and creatures of the sea are being tamed by man, but no man can tame the tongue." James said the tongue can't be tamed, but the tongue can be controlled. The tongue, to be controlled, must be guarded at all times.
Proverbs 21:23, "He who guards his mouth and his tongue keeps himself from calamity." The best way to control the tongue is to know when to close the mouth.

Truth: Even though the tongue weighs practically nothing, isn't it surprising how few there are that can hold it?

(3)  The tongue may be very small, but it's very revealing.
(vs. 9 -12) "With the tongue we praise our Lord and Father, and
with it we curse men who have been made in God's likeness."Out of the same mouth came praise and cursing. My brothers, that
should not be. Can both fresh water and salt water flow from the
same spring? My brothers, can a fig tree bear olives, or a grapevine bear figs? Neither can a salt spring produce fresh water."

Our words - how we talk and about what we talk reveals our hearts like nothing else. Our conversation is our advertisement to the world of who we are - what we're like - what we feel and what we think. Everytime we open our mouths to speak, we let others look into our minds. We are  truly known by the words of our mouth. Out tongue reveals what is inside of us. Matthew 12:34 says, "Out of the abundance of the heart, the mouth speaks." Someone has rightfully coined the phrase, "The condition of our heart determines the contents of our words."

It has been estimated that the average person will be engaged in about thirty conversations a day. This being true, then the odds are that at some point in all this speaking, our mouth is going to get us into trouble by what we say. Proverbs 10:19 (LB), "Don't talk so much. You keep putting your foot in your mouth. Be sensible and turn off the flow."

Pastor Bill