The power of our words produces different reactions and results depending on the kind of heart we have. Are we a righteous person or unrighteous? Do we have a conscience or not? Are we self-centered or do we care how our words affect others?
But those things which proceed out of the mouth come from the heart, and they defile a man. – Matthew 15:18, NKJV
…For out of the abundance of the heart the mouth speaks. A good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things. But I say to you that for every idle word men may speak, they will give account of it in the day of judgment. For by your words you will be justified, and by your words you will be condemned. – Matthew 12:34-37, NKJV
That's a heavy responsibility we have on our shoulders. God is fully aware of every word we speak throughout our lives. We will one day give account of what we said and how our words affected the lives of other people. And how we speak in this life is determined by which kind of heart we have.
King Solomon gave us a model to follow in the book of Proverbs. He provided examples of the power of words coming forth from both righteous and wicked hearts–and the different results involved:
The lips of the righteous know what is acceptable, but the mouth of the wicked is perverse. – Proverbs 10:32, WEB
An ungodly man digs up evil, and it is on his lips like a burning fire. – Proverbs 16:27, NKJV
A gentle answer turns away rage, but a harsh word stirs up anger. – Proverbs 15:1, GW
The lips of the wise disperse knowledge, but the heart of the fool does not do so. – Proverbs 15:7, NKJV
Death and life are in the power of the tongue. – Proverbs 18:21a, NKJV
The mind of the righteous person thinks before answering, but the mouth of the wicked blurts out evil things. – Proverbs 15:28, HCSB
I like the last verse there. Most of us are familiar with the phrase, "think before you speak." Solomon was the first person to teach that principle. That is one of the marks of a righteous heart. That is the mark of someone who cares how the power of his or her words affects other lives.
Is it that simple? People who are righteous always speak what's right and evil people always speak what's wrong? No. The Bible gave us a model of how we should speak if we are righteous, but we all fail. All of us are born sinners (Romans 3:23; 5:12). So we are all "evil" by nature. But even sinners have the ability to say good things because we were all created in the image of God (Genesis 1:27). Many of us have come to believe in Jesus Christ, but even believers have a hard time maintaining self-control over their tongues.
Yet, no one can tame the tongue. It is an uncontrollable evil filled with deadly poison. With our tongues we praise our Lord and Father. Yet, with the same tongues we curse people, who were created in God's likeness. Praise and curses come from the same mouth. My brothers and sisters, this should not happen! – James 3:8-10, GW
It should not happen, but it does. It is understandable for unbelievers to use the power of their words in negative ways. That fits the model of their hearts and their human nature. The image of God has been shattered in them, but not restored. But believers should reveal to God and others the model of a righteous heart because the image of God has been restored in their lives. The New Testament teaches that believers "have put on the new man who is renewed in knowledge according to the image of Him who created him." (Colossians 3:10, NKJV)
So the reason that Christians are supposed to have good hearts is because God has turned them into different people through the power of the Holy Spirit (Rom. 8:15,16; I Cor. 2:11-14). Believers have the ability to impact humanity in positive ways with the power of their words, but still battle with their old nature (known as "the flesh" in biblical terms).
I say then, walk by the Spirit and you will not carry out the desire of the flesh. For the flesh desires what is against the Spirit, and the Spirit desires what is against the flesh; these are opposed to each other, so that you don’t do what you want. – Galatians 5:16,17, HCSB
So even though there are two models of hearts in the Bible, many people fall somewhere in the middle.
Unbelievers can certainly say good things. Humanity as a whole are a good people and are able to speak well to others, but they can also be very self-centered and let their tongues loose in ways that really cause harm to those around them.
Believers are supposed to be the model of a righteous heart. We struggle, but with prayer that the Holy Spirit will win the battle over our natural tendencies, we will honor God and benefit others with the words that we speak.
Which kind of heart do you have?