Watching for False Teachers (Mt. 7:15-20)

Here’s my sermon Sunday from Matthew 7:15-20. You can check out the audio here.

A few years back, when Amy and I briefly lived outside of Missouri, I had the habit of keeping track of what was going on back in my home state. One day, I found myself reading an article about a young woman missing in a rural area just south of St. Louis. I got to the part that mentioned the last person who had been seen with her, the primary suspect, her ex-boyfriend, and I stopped, and I gasped. The name listed was none other than that of my roommate during my freshman here at Mizzou. That guy, who I shared a room with over in Hatch Hall - this quiet but popular, jovial Ag student, active in college ministry events - was the main suspect in a homicide investigation.

Now I still remember my parents dropping me off for college that fall. A small-town kid dropped off at this massive state university. And I can’t imagine how my parents must have felt - probably anxious that I’d get torn apart or led astray by all the wild kids all over this campus. I still remember - the first weekend I was here - a drunk student, making national news, by climbing an utility pole, and getting electrocuted. The campus can be crazy. But little did my mom and dad know that the real danger might have been right there, just across my room.

We’re continuing through our study through Matthew. We’re almost through this section of Christ’s teaching called the Sermon on the Mount. And in today’s passage, Matthew 7:15-20, Jesus warns us. The danger may not be out there. It may be right here in our midst. It may be closer than we think. We have to be careful. Our Lord here gives us some words to keep us safe.

He’s sitting on this mountain, declaring, “I’m the King you’ve been waiting for. And here’s the life that’s found in my kingdom.” And near the end of this sermon, He warns us: look out for those who would knock you off my kingdom path. Jesus says, be vigilant. Be discerning. False prophets are coming.

Jesus gives us here, in the verses that Matt just read, a warning along with a method. What we need to watch out for, along with how we go about doing that. We’ll get to each of those. But before we do, there is a presupposition we need to touch on.

The Presupposition

First, consider a presupposition of Jesus. The Lord assumes something that we often don’t also assume today. What’s that? That there is such a thing as truth. Even absolute truth - that stands above us. That demands our acknowledgment, as well as our allegiance. And that it’s possible to wander away from that truth. In fact, we’re vulnerable to doing just that.

Even if we’ve come to follow Christ, we’re still human. We’re still fallen. And we’re vulnerable - vulnerable to the lies of our Enemy. Think back to the beginning, to the garden, where Adam and Eve heard that voice in Genesis 3: “Did God actually say?” We still have to fend off that voice today. An unholy Trinity assails us. The world - that’s all around us. Our flesh - that’s here inside us. And the devil. Who comes after us. They all say: “You can be your own King. You can have your own Kingdom.” We’re so vulnerable.

Recently, I read the book The Escape Artist by Jonathan Freedland. It tells the story of Rudolph Vrba, a Slovakian Jew, who escaped Auschwitz, the concentration camp in Poland. He had seen Jews get off trains, coming from all over Europe, and walk immediately, unknowingly into gas chambers, and to their death.

And he miraculously escaped from that extermination camp, all so he could warn the last group of his people still alive in Europe - those in Hungary - before they got on the trains, and it was too late. But you know what? People wouldn’t listen to him. They didn’t want to believe that something so awful could really be true. And there were too many people - even fellow Jews - who would reinforce the lies - that it wasn’t really happening.

The Warning

Second, see a warning Jesus gives us here. He tells us to beware of teachers who would harm us. He gives us a call to vigilance. We’re vulnerable. Life or death is in front of us. And there are those who will shove us toward destruction. He says, “Beware of false prophets.”

What are prophets? People who speak for God, right? There can be an element of fore-telling - speaking of what will come in the future. But usually it’s more of forth-telling - proclaiming what God wants us to hear now. Jesus says there will be “false prophets.” Pseudo-prophets. Who will claim to speak for God but really won’t be. They’ll be deceitful. God called out such teachers back in the Old Testament through Jeremiah. They’re lying. I didn’t send them. Says chapter 14. What they’re saying is in their own heads. Says chapter 23.

They’ll echo that voice of the serpent. And we have to watch out for their schemes. Because many will lie. Jesus says, “Beware.”

We also must watch out, because they’ll be so deceptive. These prophets, He says, will “come to you in sheep’s clothing,” but they’ll truly be “wolves.” Dogs, pigs - that Aaron talked about - earlier in chapter 7 - they’re easier to spot. ”Wolves,” on the other hand - they come in disguise.

Recently, we had a security guard - stationed outside - for about six weeks. And as a result, we have our security team back and running again. Why was that? Well, a man visited - for several weeks in a row - that we had to ask to leave. Because he was trying to push some really wrong beliefs and was generally creeping our women out. So we had to tell him not to come back.

Now those folks stand out. They’re not hard to spot. But Jesus says the real danger is the guy with the smile, who’s carrying the Bible. More, the guy sleeping in your dorm room than the dude lurking in the bushes outside. Jesus says these false teachers are deceptive. They’re dressed like “sheep,” like pious Christians, but really they’re “wolves.”

Therefore, they’re so dangerous. They’re “ravenous,” as Jesus says. They’re hungry. They want to eat you. They’re greedy. They want to rob you. Therefore, we have to watch out. Our we’ll be consumed by them. Ezekiel, in chapter 22, calls out the leaders of Judah, saying they’re like “wolves tearing the prey, shedding blood, destroying lives to get dishonest gain.” That’s the effect of these false teachers.

Some of you probably remember the video shared right at the beginning of the pandemic - called “Plandemic.” Covid was all made up - to take away your freedom, to tank the economy, etc., etc.. Eventually, it gotten taken down. But it ended up getting people killed. My wife, recovering from cancer, worked in the Covid unit over at University Hospital, and she saw the results of those lies. Jesus warns us of people who will put on disguises and come to us with lies — to harm not just our bodies, but also our souls. We have to beware of these false teachers; otherwise, they’ll destroy us.

Well, what is the message of these prophets - that Jesus is warning about here? I think we can learn much from the context. Think back to the passage Aaron handled so well - just a couple of weeks ago, in the verses just before:

Matt. 7:13 “Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many.

Matt. 7:14 For the gate is narrow and the way is hard that leads to life, and those who find it are few.

Today, we say, “Choose your path. Go your own way. Speak your truth. You be you.” Pluralism. There are many ways to God. Universalism. We’ll all be ok in the end anyhow. No one goes to hell - except maybe Hitler. That’s what our culture says today. There are messages that come from, we’ll say more of the left, that tell us to live our own way. That freedom is what it’s about. Relativism. There is no absolute truth. Or any authority over our lives. Teachers surround us, saying those ideas today. You don’t need God. You can be your own god. And they’ll destroy us, friends.

There are also prophets shouting more from our right. Think about the wider context of the Sermon on the Mount. Who are the villains, that Jesus keeps calling out? The Pharisees, right? They surely have to be in Christ’s mind here. What are they yelling out? Legalism. By being a good person - and living a moral life - you can please God. But their holiness isn’t real. It’s just outward. And that religion also has no need for God. It’s just using God to make us feel better about ourselves. We hear that message all the time today - and not just from people who are religious - and it’s just as deadly.

Also so dangerous today are Christian nationalism - that says being a good American is what it’s all about. Or a prosperity “gospel” that says God wants to make you healthy and rich. Lots of prophets are peddling both of those messages today. And they’re often the same people. Trying to lead us down a road that leads to death.

We have to look out, church. But, as we do, we have to be wise. You’ve heard of the “five second rule.” Back in 2016, a Rutgers University microbiologist put it to the test and found that, no matter how soon you grab that food from the floor, it’ll still end up covered with bacteria. The rule’s just dumb. But it’s more than likely not going to kill you.

We have to grasp that not all teachings of are equal importance. What we believe about how the end times are gonna happen, and what we believe about why Jesus came to die on the cross - they’re not equally serious - or dangerous. If we don’t get this, we’ll go around labeling everyone who disagrees with us as false prophets. And that won’t make for a fun household - or city - to live in.

We also have to recognize that some people will just get confused. And yeah, that includes you and me. And we probably shouldn’t be labeled a wolf. We all have things we’ve believed in the past that kind of embarrass us today. Like when Amy and I got married, and she asked why I had all the jugs of water stored in my attic. You know, for Y2K, when all the computers melted down and all the utilities shut down. Think about it: if what I said is true, that means we probably hold beliefs today that will embarrass us tomorrow. We may be in error. Now. So, we may need to be corrected. But it doesn’t have to mean we’re evil. If we don’t grasp this, we’ll walk around playing “duck, duck, damned” all the time. And that’s certainly not what Jesus has in mind here.

But He does call us to vigilance. False teachers will try to harm us. They’ll seek to deceive us and destroy us. And we have to be ready. Now, as many of you know, my wife is doing quite well, but the past few years have been so hard, as she’s gone through cancer treatments. Recently, I was talking to a friend who lost a family member to the disease. But his loved one died, because a Kansas City pharmacist had diluted her chemo drugs - along with those of many others - and had pocketed the profits. It made national news. The man ended up getting 40 years. We have to be careful. Jesus is talking about eternity here. Life and death.

The Method

So a question naturally arises. If these prophets are so dangerous, yet they’re so deceitful and deceptive, how can we protect ourselves? How can we “beware” of them? What are we supposed to look for? Third, see a method Jesus gives us. Christ tells us to protect our family by observing teachers’ fruit. He gives us a call to discernment.

Now before we get to that question, what we should keep our eyes open for, there are a couple of foundational things we have to understand. We have to first remember where our actions comes from.

There’s a passage in Matthew 12 that we’ll get to one day, that helps us explain today’s passage even further. Listen to verses 33-37.

Matt. 12:33 “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.

Matt. 12:34 You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks.

Matt. 12:35 The good person out of his good treasure brings forth good, and the evil person out of his evil treasure brings forth evil.

Matt. 12:36 I tell you, on the day of judgment people will give account for every careless word they speak,

Matt. 12:37 for by your words you will be justified, and by your words you will be condemned.”

I want to bring your focus to verse 34. Jesus says, “For out of the abundance of the heart the mouth speaks.” And then He says, in the following verse, that out of a person’s “treasure,” what’s there inside of him or her, comes things good and bad. What’s He saying? Our actions spring out of our hearts. They flow out of the center of who we really are. When Jesus talks about fruit here, he’s talking about our deeds. And the movement is from root to fruit. Our fruit we produce on the outside. It demonstrates what we truly are on the inside. Our root.

Think about the apologies we see today - from celebrities and athletes. They commit sexual assault. Or they punch somebody in a bar. Maybe they say something racist or sexist. What do they say? “What I did. That’s not who I am.” But doesn’t Jesus say the exact opposite? That’s exactly who you are! “Out of the abundance of the heart the mouth speaks.” The fruit we bear flows out of our true nature. As Jesus says in verse 17, healthy trees bear good fruit. Diseased trees, though, bear bad fruit.

Here’s a second thing we have to understand: how transformation takes place. If we want to see change in our lives, we have to start with our hearts. Paul Tripp likes to explain it this way. If we walk outside right now, still in the dead of the winter, and we start stapling apples to our trees, our neighbors are going to think we’re nuts. “Hey, Bob, check out my apple tree!” No. That’s not the way it works at all.

But that’s how we often try to approach change. We try to clean up our speech, maybe do a few good deeds - to try to become a good person. But that won’t work. We also can’t produce fruit that’s contrary to our nature. We need our hearts transformed. To where we’re treasuring Christ most of all. And our actions then flow out of that.

Now when Christ saves us, He makes us born again. He gives us new hearts. He makes us a new type of tree. No, Jesus says, in verse 16, grapes can’t be gathered from thornbushes. You can’t get figs off of thistle plants. But God can make us, by His grace, and for His glory, new kinds of plants. He can change us at the root of us, so that we then produce good fruit. Now, even as Christians, we’re still susceptible to those lies - from the world, flesh, and the devil. Fundamentally, we are a different type of tree. But we still have to fight to treasure Christ. And grow and change.

2 Corinthians 3:18 gives us the pathway to having transformed hearts that result in loving actions. “And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another.” We become what we behold. Who we are is determined by what we worship. And what we worship determines what we do.

Now what does all of this have to do with false prophets? Well, if our root leads to our fruit - if we want to test what kind of person someone is - we can also go the other direction. We can trace from fruit to root. That’s the method, the approach, that Jesus gives here. He says, in verse 16 and in 20, you will recognize them by their fruit. If it’s good, if it’s healthy, so also must be the tree. We have to be fruit inspectors - that is if we want to keep our family safe.

Now what type of fruit is Jesus talking about here? Obviously not apples or pears. It surely has to start first with the teacher’s teaching. Right? If it doesn’t fit with God’s word - if it doesn’t go with the gospel of Jesus - we can know for sure it’s a false prophet we’re dealing with. But that’s not always that easy to grasp. We can easily get confused. The teacher may use all the right words. But maybe with different definitions. They may even be teaching something that’s right, but there are other problems we have to see.

We also second need to look for a teacher’s attitude. In John chapter 10, Jesus calls himself the “good shepherd” who “lays down his life for the sheep.” He then contrasts Himself with the “hired hand.” Who doesn’t own the sheep. And who really doesn’t care. A wolf comes and he runs. “False prophets” are in it for themselves - for money, for fame, for power, maybe even sex.

As my friend Rik Maxedon puts it, “Jesus uses what He has to benefit you. False teachers use what you have to benefit them.” Now this won’t always be easy to discern - and even faithful pastors and leaders struggle with their motives - but the prophet’s attitude is something to watch for.

We also third should look out for a teacher’s conduct. This is probably the main thing Jesus is talking about here. Does he or she exhibit the fruit of the Spirit - from Galatians 5 - “love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control?” Or maybe instead the “works of the flesh” listed in that same passage? If it’s the latter - if the fruit is all bad - you can probably guess there’s something wrong with the root. And you’re dealing with a teacher that’s false.

Today, you can hear someone preach or read articles people post, and you can get a really good impression. But then you see them on Twitter and see something very different. Or see them out in the community, and you don’t glimpse Jesus through them at all. Maybe their teaching seems even to be true. But, is there love - from this prophet, this teacher? If not, you’d better watch out.

We should also fourth think about a teacher’s influence. What’s the fruit in the followers of this prophet? Leaders make followers. They’re making disciples. What do those disciples look like? Do they teach bad doctrine? Do they have selfish attitudes? Are they complete jerks? Leaders reproduce themselves. You can see a lot in their little images walking around.   

Now we have to look for this fruit, again, because it’s a matter of life and death. Hear what the Lord says in verse 19 again: “Every tree that does not bear good fruit is cut down and thrown into the fire.” Dead, bad trees end up as firewood. And these false teachers will end up in hell. They’re for sure also going to take others with them. So we have to take care that we’re led not astray, and we don’t end up right there, too.

Now as we go about fruit inspection, we also have to be careful. That’s because it’s so easy to become critical. You can easily turn into a heresy hunter, finding what you think is a heretic behind every bush. You might find yourself writing a “discernment blog,” where you’re constantly tearing into your brothers and sisters in Christ. And you can find yourself producing some pretty rotten fruit yourself. My friend Tyler St. Clair, a pastor in Detroit, says in dealing with wolves, we still have to act graciously, pointing out error, calling them to repentance, having a Christlike disposition - even with those who are leading others astray.

Here’s another thing we also have to remember. Discerning someone’s fruit can take a significant amount of time. You may have heard about the family in China, that adopted a dog. They thought they had taken a Tibetan Mastiff into their home. A couple of years later, they realized their mistake. Actually, the animal was a bear. It got to 250 pounds, and it wouldn’t stop eating and growing. It definitely was not a dog! And they had to have it taken away. So they didn’t all get eaten! The fruit may not appear until later. It may take quite awhile. But the truth will be evident one day.

And this also applies to the teacher’s disciples. I remember back in the day when Rob Bell was really popular. His Nooma videos left a lot of people like me  thinking his theology was really off. He then made it clear. His book, called Love Wins, said there were many ways to God, and that everyone would eventually be saved. Now I look at his fans today, and many of them are long gone. They’ve turned their backs on Christ. I also think of the Christian political movements of the 80s and 90s, the so-called “moral majority.” Those who grew up listening to that are the ones sharing the conspiracies on Facebook. And many of their kids will never step foot in a church ever again.

We have to beware of false prophets. Exercise vigilance. We have to look at their fruit. Show discernment. Otherwise, we’ll end up in a bad place - and harm those around us.     

Two Questions About Application

Now before I wrap up, there are a couple of questions I want to address - those that deal with how we apply these words.

First, what action do we take when false prophets are revealed? Now in that same article, from my friend Tyler St. Clair, he still says we have to act urgently. We have to act boldly. Hear me: we don’t pet wolves. We don’t feed them. We don’t let them into our homes, so they can devour our children. We have to treat them differently than sheep - or even goats. Or people are going to die. So this means church discipline, if people are members of our church. Or barring people from our worship, even if they’re not. People have to be warned. Sometimes called out publicly. People have to be protected.

Second, how can we protect ourselves from the influence of false teachers? How can we be proactive? How can we grow in vigilance and discernment? Here are four words on that.

First, we must root ourselves in God’s word and in His gospel. We have to study our Bibles and know what they teach, if we want to keep ourselves safe. We’re all theologians. Are you a good one or a bad one? Are you susceptible to false messages and messengers?

We also have to marvel at His good news. And hold who Jesus is and what He’s done near and dear. If we’re rooted in Christ - in His life, death, and resurrection for sinners - if we love the true gospel - we won’t fall for counterfeit ones.

Second, we have to exercise caution with the media we consume. Books, podcasts, social media, for sure. It used to be that people had to have a platform - or one they could use, at least - to get their message to the masses. And it wasn’t easy to get. Now it is. Now days, everyone has that. Right on their phone. Watch what you consume. Don’t get your Bible teaching off TikTok. Sure, the authors on our resource table aren’t a part of Karis. But they’ve been vetted by your leaders. That leads to my next point.

Third, we must plant ourselves deeply in a local church - here or somewhere else - that preaches the Bible and the gospel. Get your teaching primarily from pastors you know. Learn and grow mainly through believers you love. People who know you. Whose fruit you can see.

I can’t tell you how bizarre it has been in this season, to have someone leave our church because of a YouTube video they watched - when we literally baptized them and performed their wedding. I know Satan has to really love that. Sure, podcasts can be great. But they shouldn’t be your primary diet. And you should have people around you, helping you sort out what’s good.

On that note, fourth, we must fight to grow in humility. This may be the biggest thing. Surround yourself with believers you trust. Lean on them to sort through the messages you hear. If one of them tells you that a teacher you’re listening to is off, listen to them. If they tell you a book isn’t sound, be humble enough to consider what they say. Find those you can trust, that you can submit to, or find another church community. But realize, if you do, that the problem is more than likely with you.

Keeping Our Home Safe

Jesus teaches us here, that it’s important to keep our family safe. If you suspected there was as intruder in your home, you’d do whatever you could to protect your kids from danger. If you began to realize that one of your roommates was dangerous, you’d take drastic measures to get him out of your apartment. We have to be vigilant. We have to be discerning.

Last week, we installed two new elders here in Karis. And what an awesome day it was. But I mentioned in my sermon that another title for elder is pastor. And that pastor really means shepherd. And what do shepherds do? I listed two things. Provision. They feed, they care for the sheep. And protection. They watch out for wolves. They keep the flock safe.

Have you heard these words Paul said in the book of Acts? To the elders of Ephesus?

Acts 20:28 Pay careful attention to yourselves and to all the flock, in which the Holy Spirit has made you overseers, to care for the church of God, which he obtained with his own blood.

Acts 20:29 I know that after my departure fierce wolves will come in among you, not sparing the flock;

Acts 20:30 and from among your own selves will arise men speaking twisted things, to draw away the disciples after them.

Acts 20:31 Therefore be alert, remembering that for three years I did not cease night or day to admonish every one with tears.

It’s so important to have elders that know what God’s word says and know how to teach it. It’s also why it’s so critical that they’re wise. And that they’re brave. Wolves will come. And they have to protect God’s church.

But Jesus here isn’t just talking to elders. He’s talking to us all. Jesus tells us, His disciples, “Beware of false prophets.” And “you will recognize them by their fruits.” It’s the responsibility of us all. To look after our brothers and sisters. And not let wolves run rampant in our midst. We all have to know how to read our Bibles. And be ready to spot counterfeits when we see them. We have to be bold and courageous. Yes, involving church leaders when necessary. But if we see something, we say something. Our health, our destiny, is at stake.

But, again, even more that that, we have to watch over our own hearts. And let our brothers and sisters even help us there. We’re all prone to lies. To hear the voice of that ancient serpent. “You can’t trust Him. You can be your own King.”

We’re far more vulnerable than we realize - to false teachers Jesus speaks about here. So we have to remain humble before God and others, and hungry for His word and His gospel. Jesus says, be vigilant. Be discerning. False prophets are coming. Let’s pray.