Jesus’ teaching that the good tree bears good fruit and the bad tree bears bad fruit responds to the Pharisees’ judgment of him, slandering him as a corrupting influence and a heretic. Jesus exposes their inconsistency: if the tree is bad, then the fruit must be condemned, so it would be bad that an Israelite, freed from a demon, could now see and speak. Yet if they saw the fruit of his work as good, they must also admit that the tree itself is good. Jesus repeats what he had already mentioned about false prophets (Matthew 7:16–18): that the fruit of a tree always matches the tree, as a person’s words reveal the state of his heart. The fruits of Jesus’ life were good, while the Pharisees’ fruits—especially their words (Matthew 12:24,Matthew 12:34)—were so rotten that Jesus warned them not to commit the unforgivable sin . This shows us that when someone hardens his heart, closing himself to Jesus’ word and to the Spirit’s grace, as far as it depends on him (Matthew 12:28, Romans 11:29), evil fruits will result.
Jesus’ statement about the good tree bearing good fruit and the bad tree bearing bad fruit must be read in the context of the Pharisees’ judgment of him. They slander him by portraying him as a corrupting influence and a heretic. Jesus exposes their grave inconsistency: if the tree is truly bad, then the fruit must also be condemned. In that case, they would have to say it was a bad thing that an Israelite, freed from a demon, could now see and speak. Yet if they acknowledge the result of his work as good, they must also admit that the tree itself is good.1
Here Jesus repeats a principle he had already mentioned in connection with false prophets (Matthew 7:16–18): that the fruit of a tree always corresponds in kind and quality to the tree itself. In the same way, a person’s words and deeds reveal the state of his heart and nature. The fruits of Jesus’ life were good, while the fruits of the Pharisees—especially their words (Matthew 12:24, Matthew 12:34)—were so corrupt that Jesus warned them against committing the unforgivable sin.2
This teaches us that when someone hardens his heart, closing himself to the word of Jesus and, as far as it depends on him (Matthew 12:28, Romans 11:29), to the grace of the Spirit, evil fruits will inevitably spring from that heart.3
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.