The Tree, The Treasure, and The Tongue Text: Matthew 12:33-37
Introduction: The Inescapable Diagnosis
We live in an age that is desperate to avoid straightforward moral diagnosis. Our culture has become a master of the euphemism, the misdirection, and the blame shift. We speak of "mistakes" instead of sins, "disorders" instead of wickedness, and "unfortunate choices" instead of rebellion. We are told that the problem is always external: it is society, poverty, upbringing, or a chemical imbalance. The modern project is a frantic, sustained effort to deny the biblical doctrine of the human heart. But Jesus Christ, the great physician, will not allow us to get away with such self-deception. He cuts through all the noise, all the excuses, and goes straight to the root of the matter.
In our text today, Jesus confronts the Pharisees, who had just committed a particularly heinous sin. They had witnessed the undeniable power of the Holy Spirit working through Christ to cast out a demon, and in their venomous hatred, they attributed this work of God to Satan himself. This was not a slip of the tongue. It was a calculated, blasphemous accusation flowing from a heart thoroughly corrupted. In response, Jesus does not offer them therapy or suggest a change in their environment. He gives them a lesson in spiritual horticulture and heart diagnostics. He tells them, and us, that what comes out of a man is the truest indicator of what is inside a man.
This passage is a profound challenge to our superficial age. It teaches us that our words are not trivial. They are not disconnected bubbles of air that float away and disappear. They are fruit. They are treasure. And ultimately, they are evidence. On the final day, our words will be brought into the courtroom as exhibit A, testifying either to the grace of God that regenerated our hearts or to the poison of rebellion that still resided there. We must therefore attend to these words with the utmost seriousness, for they reveal nothing less than our eternal destiny.
The Text
"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.”
(Matthew 12:33-37 LSB)
Fruit Inspection (v. 33)
Jesus begins with an agricultural axiom, a piece of common sense that is impossible to deny.
"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." (Matthew 12:33)
The logic is relentless. You cannot have it both ways. You cannot get figs from a thistle, or apples from a poison ivy vine. The nature of the tree determines the nature of the fruit. Jesus is telling the Pharisees, "Your words, your blasphemies, are the fruit. Now, let us reason backward to the nature of the tree." They were trying to present themselves as good trees, as righteous leaders of Israel, while producing the most toxic fruit imaginable. Jesus calls this out as an absurdity. You cannot separate the product from the source.
This is a fundamental principle of reality because it is a fundamental principle of God's created order. Character precedes conduct. Being precedes doing. What you are will inevitably determine what you do and say. The modern world wants to reverse this. It wants to believe that you can be a good person who just happens to do bad things. But Jesus says no. The bad things you do are the evidence, the fruit, that proves you are a bad tree. The Pharisees' words were not an anomaly; they were a revelation. Their speech simply pulled back the curtain on the rottenness of their hearts.
This principle applies to all of us. We cannot comfort ourselves by saying, "I didn't mean it," when our words are harsh, slanderous, or impure. Jesus says the meaning was there all along, deep in the root system. The words simply brought it to the surface. Therefore, the solution to bad fruit is not to tape good fruit onto the branches. The solution is a new tree. The solution is to be born again.
The Fountain of the Heart (v. 34-35)
Jesus now drops the agricultural metaphor and moves to the direct source: the human heart.
"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." (Matthew 12:34-35 LSB)
He begins with a blistering address: "You brood of vipers." This is not casual name-calling. It is a precise theological diagnosis. He is saying they are the offspring of the ancient serpent, Satan (Genesis 3). Their spiritual DNA is serpentine. Their native language is the hiss of the Tempter. For them to speak what is truly good would be as unnatural as a snake singing a hymn. It is a category error. Their very nature, being evil, makes good speech impossible.
And then He gives the central thesis of the entire passage: "For the mouth speaks out of that which fills the heart." The heart, in biblical terms, is not just the seat of emotion. It is the command center of the entire person: the intellect, the will, and the affections. It is the wellspring of life (Proverbs 4:23). What fills that wellspring will inevitably overflow and come out of the mouth. The mouth is the bucket that draws from the well of the heart. If the well is poisoned, you cannot draw clean water from it.
Jesus then describes the heart as a "treasure" chest. Each person has a storeroom. The good man, the one whose heart has been regenerated by grace, has a good treasure. This treasure is the indwelling Christ, the fruit of the Spirit, the truth of God's Word. When he speaks, he brings forth good things from this abundant store. His words of encouragement, truth, and grace are not a performance; they are the natural overflow of a heart filled with goodness.
Conversely, the evil man, the natural man, has an evil treasure. This treasure is composed of pride, bitterness, lust, envy, and rebellion. When he speaks, he cannot help but bring forth evil things from this corrupt storeroom. His slander, his lies, his filthiness, his blasphemy, are not unfortunate slips; they are the authentic expression of his treasured corruption. You cannot fix the problem of evil speech by simply trying to talk differently. You must get a heart transplant. You need a new treasurer to manage your heart, and His name is Jesus Christ.
The Final Audit (v. 36-37)
Finally, Jesus brings this teaching to its terrifying and glorious conclusion: the day of judgment.
"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." (Matthew 12:36-37 LSB)
This is one of the most sobering statements in all of Scripture. Not just our blasphemies, not just our calculated lies, but "every careless word." The Greek word is argos, which means idle, unprofitable, or lazy. It refers to the words we speak when our guard is down, when we are not putting on a show. It is in our unguarded moments, our "off the cuff" remarks, our casual gossip, that the true state of our heart is most clearly revealed.
There will be a final accounting. God keeps meticulous records. Every idle word is on the transcript. This should drive us to terror, for who among us has a perfect record? Who has not spoken foolishly, angrily, or impurely in a careless moment? If our salvation depended on this transcript, we would all be damned.
But then Jesus says something that seems, at first glance, to contradict the doctrine of justification by faith alone: "For by your words you will be justified, and by your words you will be condemned." Is Jesus teaching a works-based salvation here? Not at all. We must understand the biblical meaning of justification in this context. Justification on the last day is not the initial act of being declared righteous before God, that happens by faith in Christ alone. Rather, it is the public vindication, the open declaration and proof of that reality. Our words do not form the basis of our justification, but they do serve as the evidence of it.
Think of it this way. Faith alone justifies, but the faith that justifies is never alone. It is a living, active faith that transforms the heart. And a transformed heart produces transformed speech. On the day of judgment, God does not look at our words to decide whether to save us. He points to our words as the public evidence that He has already saved us. The good words of a believer, imperfect as they are, testify to the good treasure of Christ within. They are the fruit that proves the tree was made good by grace. The evil words of the unbeliever will likewise be brought forth as evidence, condemning them by demonstrating that their hearts were never changed, that their treasure was always evil, and that they remained a bad tree, fit only for the fire.
Conclusion: The Gospel for Our Lips
So where does this leave us? It should leave us, first, with a profound sense of our own sinfulness. If we are honest, we know that our mouths are often fountains of foolishness and sin. We are all guilty. Our tongues have condemned us a thousand times over. This passage should strip away all our self-righteousness and drive us to the cross.
For at the cross, the perfect man, the Lord Jesus Christ, was condemned for the careless words of His people. He who spoke only what was good, true, and beautiful took upon Himself the judgment for our slander, our gossip, and our lies. He became a curse for us, so that the evil treasure in our hearts could be thrown out and replaced with His good treasure.
The gospel is the only solution to the problem of the tongue. You cannot tame it through willpower (James 3:8). You cannot fix it with self-help techniques. You need a new heart, and only God can give you one. When the Holy Spirit regenerates you, He begins the process of filling your heart with a new treasure. He writes God's law on your heart. He fills you with the love of Christ. And as He does, the overflow begins to change. The fruit begins to change.
This does not mean perfection in this life. Christians still sin with their words. But the direction of our speech has been fundamentally altered. Our desire is now to honor God with our lips. We confess our sins of the tongue. We ask for grace to speak words that build up and give grace to those who hear (Ephesians 4:29). Our words become evidence, not of our own righteousness, but of the powerful, sanctifying grace of God at work within us. And on that final day, when the transcript is read, the verdict for the believer will not be based on the perfection of our speech, but on the perfection of the One in whom we trusted. Our words will simply be the joyful echo of the verdict already secured by His blood: justified.