Pure, Proven, or Plastic – Matthew 7:15–23
We are coming near the end of the most important sermon ever preached—Jesus’ Sermon on the Mount. And it’s been a challenging journey. Jesus has not held back. If you’ve been with us over the past several weeks, you know: this is no easy message.
Jesus has been turning upside down the religious assumptions of his day—not to shock, but to purify. Not to shame, but to sanctify.. Again and again, he’s called his listeners not just to external righteousness—but to a righteousness that flows from the heart.
Let’s remember where we’ve been:
Six times, Jesus said, “You have heard it said… but I say to you.” Each time, he wasn’t just revising bad doctrine—he was rescuing people from the shallow, “checking the box” teaching of the Pharisees and calling them back to the heart of God.
He warned against doing acts of righteousness—giving, praying, fasting—just to be seen by others, but to practice them from a posture of genuine relationship with the Father.
And he called us to a radical life: one where blessing comes from meekness and mourning, where we forgive enemies, turn the other cheek, go the extra mile, seek God’s kingdom first, and refuse to judge others by a standard we do not apply to ourselves. The path He has outlined is radical. It is narrow. It is heart-deep. It is not about external performance but internal transformation. He has shown us truth and grace.
And he knows that some, under spiritual disguise, will lead others away from the very life He has come to offer.
So it’s no surprise that, as Jesus begins to land the plane, he offers a serious and sobering warning: “Beware of false prophets…”
Why? Because he knows how easily God’s desires can be distorted. He knows how vulnerable we are to spiritual deception—especially when it comes packaged in the form of “religious authority.” And He knows that the call He’s given—the narrow way of purity, mercy, loving your enemy, humility, and wholehearted devotion—is so radical, so countercultural, that it may well be challenged at every turn.
Perhaps the biggest threat won’t come from the outside world, but from within the religious community—from those who speak in God’s name but whose hearts are far from Him.
Let’s read the whole passage—Matthew 7:15–23. I want us to hear the full weight and continuity of Jesus’ warning.
Matthew 7:15-23, ““Beware of the false prophets, who come to you in sheep’s clothing, but inwardly are ravenous wolves. 16 You will know them by their fruits. Grapes are not gathered from thorn bushes nor figs from thistles, are they? 17 So every good tree bears good fruit, but the bad tree bears bad fruit. 18 A good tree cannot produce bad fruit, nor can a bad tree produce good fruit. 19 Every tree that does not bear good fruit is cut down and thrown into the fire. 20 So then, you will know them by their fruits.
21 “Not everyone who says to Me, ‘Lord, Lord,’ will enter the kingdom of heaven, but he who does the will of My Father who is in heaven will enter. 22 Many will say to Me on that day, ‘Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?’ 23 And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness.’”
The Danger of Deceptive Teachers – vv. 15-16
ILLUSTRATION – Caelie Wilkes was proud of her little succulent plant. But just when she was ready to take the next step in caring for it, she realized her efforts were all for naught. Wilkes said, “I was so proud of this plant. It was full, beautiful, just an overall perfect plant … I had a watering plan for it, if someone else tried to water my succulent I would get so defensive because I just wanted to keep good care of it. I absolutely loved my succulent.”
When Wilkes decided it was ready to be transplanted into a larger vase, she was shocked to find that the plant was plastic. “I put so much love into this plant! I washed its leaves. Tried my hardest to keep it looking it’s best, and it’s completely plastic! How did I not know this? I pull it from the container it’s sitting on … Styrofoam with sand glued to the top!”
You know… It’s funny – we can water fake things, thinking they are the real deal. They might look the part… sit in the sunlight… never wither… but also never grow… and certainly not bear any good fruit… because they’re not alive. They might be convincing, but they are counterfeit. False appearances can be pretty dangerous.
When it comes to false appearances, Jesus calls us to be discerning, not just about appearances, but about the fruit. Think about the artificial fruit you might see in a centerpiece or a store display. They look beautiful, perfectly shaped, and colorful. But try to eat them? No flavor, no nourishment—just plastic. They’re meant to fool your eyes but not your taste buds.
In the same way, these false prophets’ faith looks good on the outside—outwardly spiritual, active in ministry, maybe even miraculous. But it lacks the real life and power that comes from a heart truly submitted to God. It lacks truth and grace, or neglects one or the other.
This text is all about discernment. It’s about learning to distinguish true faith from false. It is about recognizing what lies beneath the surface—because not all fruit is genuine. Some fruit is plastic fruit—pretty and shiny, but fake, lifeless and useless.
We can be drawn to the dazzle and fail to endure. Jesus issues one of His most sobering warnings—one that presses us to examine not only the voices we follow, but also the fruit our lives bear. He says, “Beware.” Not everyone who speaks in the name of God belongs to God. Some are wolves in sheep’s clothing.
And the great danger is that they’re so convincing. They say the right things. They may even perform signs. But when you peel back the layers, the fruit is rotten. The heart is proud. The path they lead you on is NOT the narrow way of life—but the broad way that leads to destruction.
Be careful who you listen to. Be careful who you follow.
This is not casual advice. This is not a gentle suggestion. This is a siren warning from the Savior: Watch out for false prophets. False prophets exist. They don’t wear name tags. They don’t announce, “Hey, I’m here to deceive you.” They wear sheep’s clothing—they look gentle, sound biblical, seem sincere. But inwardly, they are wolves. Deception is their method. Destruction is their goal. Not harmless. Not neutral. Dangerous. They don’t just mislead—they devour.
These are not outsiders. These are not secular philosophers or Roman politicians. These are religious voices. People who claim to speak for God—but whose lives, actions, and hearts are actually far from him.
And with a warning like that, I would think we might be a little on edge here… you might be getting pretty skeptical of those sitting around you… and certainly skeptical of those who take the stage… so it’s probably important for us to ask this question…
Who might Jesus have in mind here? The context helps us to answer that…
Well, throughout this sermon, Jesus has contrasted His teaching with that of the Pharisees and scribes. Jesus is not afraid to look at the Pharisees and then address the crowd by saying, “They’re leading you astray.” They’ve substituted performance for purity. Appearance for authenticity.
Jesus is landing the plane by showing us our options and calling us to choose. You have two paths: the narrow gate and the wide gate. Two kinds of righteousness, two treasures, two masters, two ambitions… and it’s like Jesus is saying, “it’s decision time.” It’s time to decide who you will call Lord… whose kingdom you will build. Will you take the broad path or the narrow path? Will you listen to false teachers or the True Teacher? Will you obey in words alone or in deeds too? Will you build on the sand or on the solid rock?
According to Jesus there are only two ways… easy and hard – there is no middle way… entered by two gates… wide and narrow – there is no other gate… walked by two crowds… large and small (there is no neutral group), ending in two destinations, destruction and life (there is no third alternative).
This kind of talk is not politically correct in the slightest… Jesus was not a universalist… He held that true and false could not be in agreement with each other… and that those who spread lies in God’s name are false prophets… and those who would follow Jesus must watch out for them. The call for us is to carefully choose who we listen to.
False prophets may quote Scripture. They may speak with passion. They may draw a crowd. And we are warned to NOT be so easily deceived. So who does Jesus have in mind here? How will we know them? Thankfully… Jesus gives us a litmus test… He speaks of:
Two Trees, Two Fruits – vv. 16–20
He moves from sheep and wolves to good trees with good fruit and bad trees with bad fruit. The fruit reveals the tree. A healthy tree bears good fruit. A diseased tree bears bad fruit.
Notice: Jesus doesn’t say, “You will recognize them by their sermons.” He doesn’t say, “You will recognize them by their gifts or their crowds or their miracles.” He says: ‘by their fruits.’
The idea is that if someone is rooted in Christ—if their heart has been transformed—they will bear the fruit of righteousness. Not perfectly, but genuinely. But if their heart remains unchanged, no matter how religious they seem, their fruit will eventually betray them.
What is the fruit Jesus is talking about? Wolves might be hard to identify, but Jesus offers a test to help. You might mistake a wolf for a sheep… but Jesus seems to say that you can’t make the same mistake with a tree. No tree can hide its identity forever. Sooner or later it betrays itself – by its fruit. You’re not gonna get an edible fruit like a grape from a thorn or a thistle…So… What are these fruits? Let me suggest 3 Biblical fruits: character, teaching, and influence.
- Character
In this context and others, I would say fruitfulness means Christlikeness… being like Jesus… Paul uses the phrase, ‘the fruit of the Spirit’ to describe Christian character that the Holy Spirit produces in the life of the believer.
When we see Christ’s character… His love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control – we have reason to believe them to be true, not false. What’s the trajectory of their life? Do they embody the Beatitudes? Are they poor in spirit? Are they peacemakers? Are they merciful? Do they love and forgive? Honest?
- Teaching
But it’s not just in character that a prophet’s fruits are revealed… we should also pay close attention to their teaching… In Luke’s parallel passage in Luke 6:45, Jesus says, “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.”
So it’s not a potty mouth… it’s a potty heart. If a person’s heart is revealed in their words… in the same way that a tree is known by its fruit… then we have the responsibility to test teachers by their teachings.
John the apostle gives us a picture of this… he wrote to some churches who had been invaded by false teachers… and he warned them not to be deceived and he says to ‘test the spirits to see if they are from God’ (1 John 4:1). Does the teacher’s teaching align with the apostle’s teaching? And most fundamentally, do they align with Jesus? Do they point people to the narrow gate? Do they proclaim both truth and grace? So allow me to remind you once more… You can’t trust anything unless its grounded in this book…
- Influence
The third measure of their fruit that I would suggest is their influence. What impact is their teaching having on their listeners? Bad teaching leads to bad living. I think this might be what Paul is referencing when he says that bad teaching “spreads like gangrene” in 2 Timothy 2:17. False teaching upsets people’s faith, promotes ungodliness, causes bitter and unnecessary divisions. What kind of disciples are they producing? Are people growing in humility and holiness? Or in pride and judgment? The proof is in the people being shaped
I realize this is not exactly simple or straightforward… in summary… God’s truth builds the church. Falsehood destroys the church. If we care for God’s truth and for God’s church, we must take Christ’s warning seriously.
Here’s the challenge: fruit takes time. You might mistake a wolf for a sheep for a while—but you won’t mistake a bad tree forever. Eventually, the fruit will tell the truth.
Verse 19 is terrifying in its clarity:
“Every tree that does not bear good fruit is cut down and thrown into the fire.”
Jesus is not playing games. Fruitless trees are not pruned—they are burned. This is a picture of judgment. There will come a day when every false teacher will be exposed. This is serious. Eternally serious.
The Danger of Self-Deception – vv. 21–23
Jesus takes it a step deeper. The danger is not only false teachers—but false confidence. Those who claim Him as Lord but yet do not do the Father’s will…
“Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven.”
That should stop us in our tracks. These are not atheists. These are not people who rejected Jesus. These are people who thought they knew Him. Who used His name. Who did ministry. Who had charisma. Who had a résumé of miracles.
We prophesied and cast out demons and performed miracles… those seem like impressive credentials… if anyone could claim to be genuine Christians, they would fit the bill…
And Jesus says, “I never knew you.” This is sobering. Their professions of faith and their spectacular ministries, and even their public use of Jesus’ name… means nothing if not accompanied with obedience from the heart. Which means these people were not rejected for lack of spiritual activity—but for lack of spiritual intimacy.
They performed religious works, they were religiously busy… but they didn’t walk in relational obedience. Jesus says the true test is not giftedness but submission: “The one who does the will of my Father in heaven.” He shows us the difference between saying and doing. True discipleship demands more than signs… it demands a transformed life.
God’s priorities are not about flashy displays but about the heart. The kingdom of God values a broken spirit and a contrite heart… humbled before God. It values a will bent on doing the Father’s will. It values obedience over showmanship.
This is a relationship of full surrender… this decision to follow Jesus is radical and total. There is no middle ground. Jesus calls for an unconditional commitment of mind, will, and life to His will and His ways. To call Him Lord is not the same as submitting to His Lordship.
Let this passage shake any false confidence we have in spiritual activity without surrender. Jesus doesn’t just want our ministry—He wants our hearts.
Tension Today: Two Temptations in Our Time
I would like to close by applying this text to what I believe are the two greatest temptations the church is facing – two extremes that pull at the fabric of our faith. They function like opposite ends of a pendulum – and I believe Jesus would confront both with equal urgency.
- The Temptation to Dilute Truth in the Name of Love
Our world elevates tolerance as the highest virtue… the culture defines love almost exclusively as affirmation. With this in mind… the pressure is to soften or sanitize or selectively quote Scripture… I like to call this cherry picking theology.
This crowd might say, “Jesus is love,” and they’d be right… but their understanding stops short of Biblical love. The problem is not that that line is false, but that their theology is incomplete. There are voices that say, “Love means approval.” That to be loving, you must never confront, never disagree, never speak truth.
Yes, Jesus is love. He is the friend of sinners, the gentle healer, the one who welcomed children, the one who dined with tax collectors and prostitutes. AND He is also the one who overturned temple tables, who called sin what it was, who told the woman caught in adultery, “Neither do I condemn you—go and sin no more.”
The temptation today is to redefine love as the absence of offense. To avoid ever speaking hard truths because someone might feel judged. But in doing so, we can end up preaching a gospel with no cross, no repentance, no call to holiness—just a vague spirituality wrapped in nice sentiments.
And friends, that’s not love. That’s sentimentality. Real love tells the truth—even when it hurts. Real love says, “I want your freedom more than your approval.” Real love risks discomfort to save someone from destruction.
Jesus said, “The truth will set you free.” But if we never tell the truth, we leave people in bondage. This temptation is subtle. It’s wrapped in the language of compassion. But it ultimately leads people away from the narrow gate. It’s a wide, popular, culturally celebrated path—but it doesn’t lead to life.
- The Temptation to Swing Back to Legalistic Religion
Now, in reaction to that, there’s another temptation—a kind of spiritual backlash. It’s the swing of the pendulum in the other direction. Some look at the moral compromise around us and respond with anger and bitterness. They double down on rules. They want boundaries—and that’s not all bad. But the danger is when faith becomes reduced to a “scorecard.”
- Right doctrine? Check. Moral convictions? Check. Weekly attendance (on Sundays and Wednesdays)? Check and check. Tithing? Check. Strong stance against cultural sins? Check. Check. Check. There are voices that say, “Truth means being right.” That to be faithful, you must have the correct theology, vote the right way, call out sin loudly, and check all the boxes.
The danger here is subtle too. Because many of these things are good and right—until they become the standard by which we measure righteousness. We tend to start thinking that right beliefs and right behavior are the same as a right heart. But Jesus didn’t come just to make bad people behave better. He came to make dead people alive. He came to change hearts, not just habits.
And the truth is: Jesus saved his sharpest words for the religious elite—the Pharisees, the scribes. People who had theology down. People who tithed mint and cumin, but neglected mercy and justice. People who looked like healthy trees—but whose roots were rotting with pride, hypocrisy, and spiritual self-reliance. If we do not watch out, we do the same.
Every text becomes a sledgehammer. Every disagreement becomes a battleground. This crowd knows how to spot wolves, but forgets how to love sheep.
We can equate orthodoxy with intimacy. We mistake activity for surrender. We wear our convictions like badges, but our hearts grow cold and unyielding. Legalism doesn’t lead to life. It leads to either spiritual arrogance or spiritual despair. And worst of all, it can blind us to our real need for Jesus. We become so convinced we’re doing it all right—we forget how desperate we are for grace.
It is possible to win an argument and lose a soul. It’s possible to defend the truth of Scripture while violating the heart of Scripture.
Paul said: “If I speak in the tongues of men and of angels, but have not love, I am a clanging cymbal.” Friends: Truth without love is brutality. Love without truth is hypocrisy. Truth with love? That’s Jesus. That’s what we’re called to. And that’s what Jesus’ sermon is all about.
Friends, discernment is vital. But so is humility. We’re not called to be heresy hunters—we’re called to be fruit inspectors. Look for love. Look for holiness. Look for Jesus.
And Here’s the Thing: Both Temptations Miss the Heart of Jesus
Both of these extremes—grace without truth, and truth without grace—lead us off the narrow road. One path abandons truth in the name of love. The other path abandons love in the name of truth. But Jesus walked a different way. He walked the narrow road of grace and truth. John 1:14 says, “The Word became flesh and dwelt among us… full of grace and truth.” Not 50/50. Not a balance. 100% grace, 100% truth.
Jesus didn’t compromise truth to be loving. And he didn’t withhold love to uphold truth. He loved sinners without affirming sin. He spoke truth without losing compassion. That’s the narrow road—and few find it. Not because it’s hidden. But because it’s hard.
Because it requires something deeper than appearance, deeper than performance—it requires a heart that is continually surrendered, shaped, and softened by the Spirit of Christ.
And the invitation today is to resist the drift of culture and the leaven of legalism—and instead walk in the footsteps of our Savior. To live as people of truth and grace… and that’s when we bear fruit that lasts. That’s when we know Him—and are known by Him.
Jesus calls us to truth AND grace. To love AND obedience. You can tell a tree by its fruit.
He doesn’t want us to just play church. Jesus calls us to the narrow way. To genuine discipleship. To a life that doesn’t just say, “Lord, Lord,” but walks in step with His will.
He doesn’t just want your performance. He wants your heart.
He doesn’t need you to be flashy. He wants you to be faithful.
So test the fruit. Watch the voices that shape you. And most of all—make sure you know Him. Not just in words. But in full surrender. In full obedience. In full love.
So here’s the question: Are you plastic, or proven? Religious, or real? Have you known about Jesus—or are you known by Jesus? Because in the end, it’s not about what you do in His name—but whether you’re walking in His will, in truth and love, in relational obedience.”