Why Does the Bible Say Our Words Overflow from Our Heart?

The words we use are very important. Our words demonstrate the orientation of our hearts and maintaining this orientation through the power of the Holy Spirit requires constant vigilance and care of my whole self.

Seth L. Scott
women smiling and crossing hands over heart, out of the heart the mouth speaks

"A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart. For the mouth speaks what the heart is full of." (Luke 6:45, NIV)

"The good person out of the good treasure of his heart produces good, and the evil person out of his evil treasure produces evil, for out of the abundance of the heart his mouth speaks." (Luke 6:45, ESV)

"A good man produces good out of the good storeroom of his heart. An evil man produces evil out of the evil storeroom, for his mouth speaks from the overflow of the heart." (Luke 6:45, CSB) 

Have you ever said something hurtful or unkind and wondered, “Where did that come from?” Have words left your lips and even as they exit you regret their expression and wish to retract them? James acknowledged the deadly impact of the tongue when he said, “…No human being can tame the tongue. It is a restless evil, full of deadly poison” (James 3:7-8, ESV). We are told to think before we speak, but when we don’t remember to do this, where are these words coming from? Why in moments of strong emotion, anger, or pain, do our words tear down and not edify and what can we do about it?

How Does the Mouth Speak What the Heart Is Full Of?

In Luke 6, a great crowd is gathered before Jesus, seeking to hear him and be healed. Jesus describes what it looks like to be His disciple, raising the bar of the Law from “Do good to those who do good to you” (Luke 6:33) to “Love your enemies, and do good, and lend, expecting nothing in return” (Luke 6:35). Jesus expands the requirements of the Law from expecting good behavior to transforming us into His people by responding to His words with action. Jesus summarizes His higher standard by stating, “The good person out of the good treasure of his heart produces good, and the evil person out of his evil treasure produces evil, for out of the abundance of the heart his mouth speaks” (Luke 6:45).

In our culture today, we tend to think of the heart as the home of our emotions, sending chalky-tasting heart-shaped candies to one another to express our love and affection, but the biblical concept of the heart is broader than the emotions. The Bible does not distinguish between the head and the heart, combining the elements of mind, will, and emotions together with the language of an organ that can feel, think, and act. As Tim Keller explained, “The heart is not just the seat of the emotions but also the source of our fundamental commitments, hopes, and trust. And from the heart flow our thinking, feelings, and actions. What the heart trusts, the mind justifies, the emotions desire, and the will carries out.”

If our heart actually includes how we think and behave along with how we feel, then the expression of this collective wholeness demonstrates the composition of our desires through our words, habits, and behaviors. The words that flow from our lips are a sample of the content that lies within our hearts.

So then, like a pop psychology online personality quiz that reveals your “true self” you might prefer to keep hidden, are words spoken (or screamed) in moments of anger and passion somehow more accurate reflections of who we really are because they are somehow bypassing the carefully developed guardian of our Christian façade? As Sigmund Freud might suppose, are these unchecked impulses from our inner recesses truer expression of self and therefore unchangeable or irrevocable? No. Paul, James, and Peter all use similar language of war to describe the conflict that wages within us between our flesh and earthly passion and the work of the Spirit to redeem us and purify our desires (Romans 7:23; James 4:1, 7-8; 1 Peter 2:11). Our own desires, affections, thoughts, and actions are bent toward sin at all times (Romans 1:24; James 1:14), but by the grace of God (Ephesians 2:8), conviction and faith by the Spirit (John 16:8), and redemption through Jesus (Romans 3:24), this natural heart state is being transformed (2 Cor. 3:18). This is the message of the gospel.

Jesus’ point in this passage is not that we must will ourselves toward holiness, but that it is through relationship with Him that the desires of our heart are transformed, cleansing the outward expression of our hearts through our words and actions to now reflect Him in place of our own desires (James 4:6-8).

What Does This Mean for Christians When We Open Our Mouths?

What does this mean for Christians who are still “in process,” seeking to put to death the desires of the flesh each day and direct our hearts towards the Spirit (Romans 8:5-11)? Martin Luther once suggested, “Whatever your heart clings to and confides in, that is really your god.” The content of our heart is developed by the direction and content of our affections in a reciprocal but learned process. In the same way that we develop a taste and desire for fast food over artichokes and kidney beans, our daily habits shape our desires and orient our hearts. When Jesus says in Matthew 12 that “out of the abundance of the heart the mouth speaks” (v. 34), He follows it up by saying, “I tell you, on the day of judgment people will give account for every careless word they speak, for by your words you will be justified, and by your words you will be condemned” (v. 36).

Our natural bent and direction is toward the desires of the flesh. The orientation of our hearts in learning to receive and reciprocate God’s love takes practice. As James K. A. Smith explained, “To be conformed to the image of His Son is not only to think God's thoughts after him but to desire what God desires. That requires the recalibration of our heart-habits and the recapturing of our imagination, which happens when God's Word becomes the orienting center of our social imaginary, shaping our very perception of things before we even think about them” (You are what you love, 2016, p. 85). As Christians, we have been justified through the blood of Christ (Romans 5:9), but we are also in the process of being sanctified as well (1 Peter 1), meaning that the Holy Spirit is working in us to conform us to the image of Christ bit by bit. It is a continuous process that requires active attentiveness to avoid “careless” or “useless” words (Matthew 12:34) slipping out at times when our diligence wains or our flesh wins. These moments are opportunities to remind us of our prior state as sinners saved by grace as well as our hope and longing for His coming restoration and glorification when we no longer struggle with this body of sin (Romans 8). Directing the affections of our heart is not accomplished by willpower or good deeds, but through the merciful work of the Holy Spirit on our behalf (Romans 8:26-27).

5 Things to Consider before Speaking

Because our mouths often engage before our brain is aware, what are some habits and behaviors we can consider to purify the flow from heart to mouth?

1. Remember that we are holistic beings.
In the same way that the heart is not just the emotions but a combination of our thinking, feeling, and actions, the expression of this heart is influenced by more than just our thinking or emotions. Remembering that we are holistic beings means acknowledging that we can get “hangry,” saying or doing things we wouldn’t normally do because we are tired, hungry, and overwhelmed, and our willpower and capacity to resist temptation is impaired. Sometimes the holiest thing we can do is get a good night’s sleep. Holiness, and the expression of our heart of holiness demonstrated through our words, doesn’t develop spiritually in isolation from our physical and emotional self. Maintain healthy rhythms in your life with nutrition, exercise, sleep, and relationships. Don’t initiate tense conversations when you are exhausted or hungry or distracted. Our capacity to avoid the lure and enticement toward sin through our words and actions is limited because we are holistic beings, influenced by the weakness of our bodies.

2. Keep the reservoir of your heart properly stocked and connected.
If the words of our mouths flow from the abundance of our hearts, then the desires of our heart should be oriented toward Christ. As Jesus explained in Mark 7:18-23, food cannot defile us because it only enters the stomach and not the heart, but it is what we allow to enter our hearts that then comes out through our words and our actions. When your children start their day singing “Baby Shark,” that captivating tune will forever retain a corner of your consciousness and you will be humming it when you ride the elevator to work because it becomes an overflow of your heart. In John 15, Jesus explains how our capacity to bear good fruit as branches is directly related to our connection with Him as the Vine. “I am the vine, you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing” (John 15:5). As James expressed, in the same way that a salt pond cannot produce fresh water (James 3:12), a heart filled with mixed affections or sports trivia or romance novels cannot produce Godly, edifying speech. God’s Word in, God’s words out (Psalm 1:2; 119:11; 37:31).

3. Expand your options for emotional expression.
Emotions are complex with their interpretation requiring insight around causes, history, perception, physical state, and word meaning. In the same way that Romans 8:26 acknowledges that the Holy Spirit works on our behalf to give words and interpretation to our groanings, to avoid saying the wrong thing we can increase our options for emotional expression by learning more words for how we feel. We should use lists of emotional words, like the Feelings Wheel, and consider each word, connecting that concept to an experience in our past and how we felt then and how we feel now. Expanding our emotional insight and language improves our emotional expression to resolve emotions appropriately.

4. Regularly recalibrate.
Because we retain elements of our flesh in this sinful body while we wait for redemption, the desires of our hearts need regular recalibration to orient them toward God and conformity to Christ. We can check our calibration regularly through time in God’s Word; accountability and discussion with friends and mentors; time in prayer and journaling with God; and by evaluating our desires by considering where our thoughts, time, and money go.

5. Give grace liberally to receive grace.
Proverbs 18:24 explains that to have friends, we need to be friendly. Grace and forgiveness work the same way. When we express careless words we wish to retract, a person who has done the same and received grace and forgiveness for that fault is more likely to extend it to us as well. We extend forgiveness to others when we are wronged because we know we also need forgiveness. Jesus’ parable of the unforgiving servant in Matthew 19:21-35 demonstrates this vividly with the recognition that the depth and extent of God’s forgiveness toward us should motivate us to forgive others well because the debt of offense toward us is minuscule in comparison to His forgiveness of our unpayable debt of sin to God.

So, what does it mean that the mouth speaks what the heart is full of? It means that the words we use are very important. “Death and life are in the power of the tongue” (Proverbs 18:21a). Our words demonstrate the orientation of our hearts and maintaining this orientation through the power of the Holy Spirit requires constant vigilance and care of my whole self. The words I use can reveal whether I am walking by my own strength or walking in the Spirit through connection to the Vine. Because we are all in the process of being transformed, slips and starts on this journey with one another remind us of the grace bestowed upon us through Christ and provide an opportunity to express the forgiveness we ourselves received, exercising the reorientation of our heart toward God even as we support others to do the same.

Photo credit: ©GettyImages/fizkes


Seth L. Scott, PhD, NCC, LPC-S is an associate professor of clinical mental health counseling at Columbia International University in Columbia, South Carolina and provides clinical counseling and supervision in the community through his counseling practice, Sunrise Counseling. Seth, his wife, Jen, and their two middle school children enjoy outdoor activities, reading together as a family, board games, and meeting people through Jen’s pottery business at galleries and festivals.


This article is part of our larger resource library of popular Bible verse phrases and quotes. We want to provide easy to read articles that answer your questions about the meaning, origin, and history of specific verses within Scripture's context. It is our hope that these will help you better understand the meaning and purpose of God's Word in relation to your life today.

No Rest for the Wicked
Fight the Good Fight
Wait on the Lord
With Contrite Heart and Spirit
Faith Can Move Mountains


Originally published November 13, 2020.