Death and life are in the power of the tongue. (Proverbs 18:21)
The biblical teaching is clear—our speech has tremendous potential for good or for evil. The power of life and death that resides in our tongues applies both to our own lives and to the lives of others.
Our words can lead us in the way of life or the way of death; they can also bring others along either of these paths. God will hold us accountable for our words. They are thus a source of life or death for us. This is true in large part because our words reflect the condition of our hearts. They serve as an external gauge for measuring the precise temperature of our internal heart’s disposition. Yeshua teaches about this in Matthew 12:33-37:
Either make the tree good and its fruit good, or make the tree bad and its fruit bad; for the tree is known by its fruit. You brood of vipers, how can you, being evil, speak what is good? For the mouth speaks out of that which fills the heart. The good man brings out of his good treasure what is good; and the evil man brings out of his evil treasure what is evil. But I tell you that every careless word that people speak, they shall give an accounting for it in the day of judgment. For by your words you will be justified, and by your words you will be condemned. (NASB 1995)
I know of few verses in all Scripture more spine-chilling than the last two of this passage: “I tell you that every careless word that people speak, they shall give an accounting for it in the day of judgment. For by your words you will be justified, and by your words you will be condemned.” These verses, however, must be seen in their context. Careless words are a problem because they reflect a careless heart: “Out of the abundance of the heart the mouth speaks” (Matthew 12:34).
Derek Prince shares the following amusing and insightful anecdote in his book Faith to Live By:
As a hospital attendant with the British forces in North Africa during World War II, I worked closely with a Scottish doctor in charge of a small field hospital that cared only for dysentery cases. Every morning as we went the round of our patients, the doctor invariably addressed each one with the same two sentences: “How are you? Show me your tongue!”
As I participated in this medical ritual each day, I observed that the doctor was much more interested in the state of the patient’s tongue than in the answer that he received to the question, “How are you?” I have reflected many times since that the same is probably true of our relationship with God. We may offer God our own estimate of our spiritual condition, but in the last resort God, like the doctor, judges mainly from our tongue.
An almost identical observation is made by a Christian teacher from quite a different era and tradition, Francis de Sales.
In Introduction to the Devout Life, he writes,
Physicians learn about a man’s health or sickness by looking at his tongue, and our words are a true indication of the state of our souls. “By your words you will be justified and by your words you will be condemned,” says the Savior.
If our hearts are right before the Holy One—if they have been circumcised in Messiah, renewed in the Spirit, and surrendered fully to God in love and devotion—then our words will reflect our transformed condition and be favorably received on high.