"Biblical Principles of Sound Speech - Our Heart and Our Mouth"

by Whitney V. Myers

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"But the things that proceed out of the mouth come from the heart, and those defile the man" (Matthew 15:18).

Today's lesson is the third in a series on Biblical Principles of Sound Speech.

     Consider.  Think for a moment.  Do you agree with Jesus' statement in Matthew 15:18 that what we say comes from what is in our heart?  

     Read - Matthew 15:1-20.  This passage will provide the context for today's lesson. 
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What We Say Defiles Us in God's Sight

     When Jesus spoke to the Pharisees and scribes in Matthew 15:1-20, Jesus was speaking to people who did not (yet) believe in him or accept his authority.  The concept of the relationship between our heart and our mouth still applies to us today as believers in Christ and also applies to non-believers.  What we take into our hearts, or allow into our hearts, determines the quality of our speech.

Jesus turned the discussion from handwashing (Matthew 15:2) to the more important subject of being clean in our hearts, speech, and thinking.  "After Jesus called the crowd to Him, He said to them, 'Hear and understand.  It is not what enters into the mouth that defiles the man, but what proceeds out of the mouth, this defiles the man' " (Matthew 15:10-11).  The Greek word for defile is koinoó, which means unclean, pollute, or desecrate (Ref. 1).  "Jesus replaced the normal Jewish understandings of defilement with the truth that defilement comes from an impure heart, not the violation of external rules" (Ref. 2 below).

In Matthew 15:11 and Matthew 15:18, the Greek word for man is anthrópos, which is the generic term for mankind; the human race; people, including women and men (Ref. 3). 

Our Heart is the Source of the Evil and the Good We Speak

     When Jesus spoke about the heart of man in Matthew 15:15-20, he spoke a concept that was familiar to his Jewish listeners.  The Hebrew word for heart is leb, which means inner man, mind, will, heart (Ref. 4).  The Hebrew word, leb (heart), occurs over 500 times in the Old Testament (Ref. 4).  The prophet Jeremiah said, "The heart is more deceitful than all else and is desperately sick; who can understand it?" (Jeremiah 17:9).  David prayed, "Create in me a clean heart, O God, and renew a steadfast spirit within me" (Psalm 51:10). 

In the New Testament, the Greek word for heart in Matthew 15:18 and in almost all New Testament occurrences is kardia (Ref. 5).  Kardia occurs over 150 times in the New Testament (Ref. 5).  Kardia means the heart; mind, character, inner self, will, intention (Ref. 5).  In Matthew 15:18, Jesus is saying that the evil that comes out of our mouth comes from what is in our heart.

Jesus also said, "The good man out of the good treasure of his heart brings forth what is good; and the evil man out of the evil treasure brings forth what is evil; for his mouth speaks from that which fills his heart" (Luke 6:45).

Below I have included a "HIPO" (Hierarchical Input Process Output) chart that I prepared many years ago when I first taught this lesson on Sound Speech to my Adult Sunday School class at church.  At the time, I was working as a computer programmer for a large company.  The chart illustrates examples of healthy and unhealthy inputs we take into our hearts.  Our senses also can influence our heart.  Our mouths are our primary output device (Matthew 15:11, 18).  In today's culture, with texting, tweeting, instant messaging, and email, we should include our "fingers" as output devices as well.  The concept still applies.

Figure 1 - What We Say Comes From Our Heart - by Whitney V. Myers

It is Important to Guard What We Take into Our Heart

     The purity of what we take into or allow into our heart affects the quality of what we say.  As per the examples in Figure 1 above, we need to be careful about our entertainment choices and being around unwholesome speech because these can contaminate our thinking.

The apostle Paul was quite clear when he described what we should think about.  "Finally, brethren, whatever is true, whatever is honorable, whatever is right, whatever is pure, whatever is lovely, whatever is of good repute, if there is any excellence and if anything worthy of praise, dwell on these things" (Philippians 4:8, italics added).

David said, "How can a young man keep his way pure?  By guarding it according to your word" (Psalm 119:9).

Solomon wrote, "Above all else, guard your heart, for everything you do flows from it" (Proverbs 4:23).

     Apply.  Pray and ask God to bring to your mind the steps you should take to guard your heart and to improve the purity of your thinking (Philippians 4:8).  As part of your action plan, read and meditate upon God's word daily (Psalm 119:9). 

Related Lessons
"Biblical Principles of Sound Speech - Be a Good Example" (Titus 2:7-8)
"Four Characteristics of Sound Speech" (Ephesians 4:29)
"Biblical Principles of Sound Speech - A Time to Be Silent" (Ecclesiastes 3:7)

References
1.  https://biblehub.com/greek/2840.htm
2.  The NIV Study Bible, Zondervan Bible Publishers, 1985, note on Mark 7:20
3.  https://biblehub.com/greek/444.htm
4.  https://biblehub.com/hebrew/3820.htm
5.  ​https://biblehub.com/greek/2588.htm