You will know them by their fruits. Grapes are not gathered from thorn bushes, nor figs from thistles, are they? So, every good tree bears good fruit, but the bad tree bears bad fruit. A good tree cannot produce bad fruit, nor can a bad tree produce good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. So then, you will know them by their fruits. (Matthew 7:16–20)
After warning about false prophets in Matthew 7:15, Jesus tells us what to watch for in identifying them. Because they are so extremely deceptive and dangerous—ravenous spiritual and moral wolves in sheep’s clothing—the Lord would hardly have left us without means of determining who they are.
Jesus assures us that we “will know them by their fruits.” A fruit tree may be beautiful, decorative, and offer pleasant shade in the summer. But its primary purpose is to bear fruit, and it is therefore judged by what it produces and not by how it looks.
There is no need to be deceived if we look closely. It is the cleverly deceptive false prophet that Jesus is speaking about here. No one needs help in deciding that a tree is bad if it bears shriveled, discolored, and obviously rotten fruit—or no fruit at all. It is the tree that appears to bear good fruit, but does not, that is deceptive.
On the other hand, it is possible for grapes to be stuck on thorn bushes and for figs to be stuck on thistles. From a distance they might appear to be growing on real fruit trees. Because the fruit is genuine, naive persons might conclude that the tree itself also has to be genuine. But in the end, a person’s basic character—his inner motives, standards, loyalties, attitudes, and ambitions—will eventually show through in what he does and how he acts.
Sir Godfrey Gregg