The Warning of Jesus

Several months ago, I had the opportunity to speak at a church about our ministry and vision for East Africa. After the service ended, I stayed in the foyer to greet and talk with members.

I’ll never forget what happened next.

A man came up to me and said, “Let me give you some advice. I’ve been going to church for many years and heard a lot of missionary presentations. You were far too negative in what you talked about. Who cares about cults? I want to hear something more positive, about the gospel being shared and Africans coming to know the Lord.”

Now, in all fairness, maybe I wasn’t as balanced as I could have been. And I certainly want to see the conversion of many Africans through the proclamation of the good news of Jesus Christ! Nevertheless, I think that his critique ultimately lacked biblical support. Jesus Himself warns us against those who seek to overthrow our faith in the Sermon on the Mount. So for the next couple of weeks, I want to briefly look at Christ’s words in Matthew 7:15–23.

In these verses, Jesus warns us that we must guard against spiritual deception. Why? As Jesus explains in verses 15–20, deceivers are dangerous:

Beware of false prophets, who come to you in sheep’s clothing but inwardly are ravenous wolves. You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles? So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus you will recognize them by their fruits.

Here we recognize a hidden danger. Jesus begins with the word “beware,” a command. This is not optional, not a suggestion, not a merely good idea. Our Savior requires us to beware of false prophets. And notice that He portrays these false prophets as an active concern, not a rare or occasional challenge. We’re to constantly be on guard against them because they’re always among us.

So who are these false prophets? They claim to speak for God but entrap others through their lies. In the New Testament, we see that they are greedy, arrogant, immoral, and ungodly. But they also impersonate true Christians—they do their work in “sheep’s clothing.” False prophets seldom tell you that they reject the faith; instead, they’re ravenous wolves who actively seek to destroy Christians.

If this is true, how can we recognize them? Jesus provides us with an exposing test: Recognize them by their fruits. Most directly, these fruits are what Jesus has laid out throughout His sermon. Here we find two foundational kinds of fruit—(1) belief in Jesus, and (2) following Jesus’ teaching—in other words, belief and behavior. Both kinds of fruit need to be tested.

To underscore His point, Jesus states the obvious. Grapes can’t come from thornbushes, and figs can’t come from thistles. Plants only produce what is in their nature to produce. Only a healthy tree that bears good fruit; a diseased tree will produce bad fruit. And in this comparison we see that there’s no neutrality. All trees are bearing fruit; the question is, what kind? If you know the fruit, then you can tell the tree. Again, we see Jesus’ seriousness: All of the trees that do not bear good fruit are condemned (“thrown into the fire”). This is the same warning that John the Baptist gives earlier to the Pharisees in 3:7–10.

Finally, in verse 20 Christ repeats Himself: “you will recognize them by their fruits.” All Christians are commanded to be “fruit testers” by the very Lord of Glory.

Which leads me to ask: How seriously do we take spiritual deception? Do we recognize the danger? Are we prepared to test the fruit of those who claim to speak for God, either in what they teach or in how they live?

Let’s not forget that Christ’s command applies to His followers everywhere. How can you and I help our brothers and sisters in Christ around the world to recognize and resist deceivers? False prophets aren’t just a danger only here in America or the West; such people are seeking to overturn the revealed truth of Christ globally.

Next week, we’ll examine Jesus’ second reason for warning us against spiritual deception.