43 “For no good tree bears bad fruit, nor again does a bad tree bear good fruit, 44 for each tree is known by its own fruit. For figs are not gathered from thornbushes, nor are grapes picked from a bramble bush. 45 The good person out of the good treasure of his heart produces good, and the evil person out of his evil treasure produces evil, for out of the abundance of the heart his mouth speaks.

46 “Why do you call me ‘Lord, Lord,’ and not do what I tell you? 47 Everyone who comes to me and hears my words and does them, I will show you what he is like: 48 he is like a man building a house, who dug deep and laid the foundation on the rock. And when a flood arose, the stream broke against that house and could not shake it, because it had been well built. 49 But the one who hears and does not do them is like a man who built a house on the ground without a foundation. When the stream broke against it, immediately it fell, and the ruin of that house was great.” – Luke 6:43-49 ESV

Whether they realized it or not, Jesus was presenting His disciples with a radically different standard for measuring a righteous life. Inclusion in the coming Kingdom of God was not going to be based on ethnicity or outward adherence to a set of rules and regulations. The disciples, as Jews, had grown up believing that their Hebrew lineage and their personal attempts to keep the Mosaic Law would somehow earn them entrance into the Kingdom. But as they listened to Jesus speak, it must have seemed like He was raising the bar and the entrance requirements, demanding from them a much higher standard than was humanly possible. One can almost visualize the 12 disciples glancing at one another in confusion and with growing concern as they listen to Jesus speak. All His talk of loving their enemies, suffering for His name’s sake, and removing the log from their eye must have left them scratching their heads and questioning their decision to follow Him. They had signed up to be early adopters of the Kingdom life, but now they must have been having second thoughts. And Jesus was far from done.

He follows up His parable about the blind leading the blind with another parable about two kinds of trees. But with His change of illustration, Jesus remains focused on the topic of inner transformation. For a blind man to effectively and safely lead another blind man, he will have to have his sight restored. For a disciple to become an effective teacher, he will first have to be an obedient and attentive student. He will need to internalize his teacher’s wisdom before he can impart it to others. And before a man can be qualified to point out the flaws in another, he will first need to get his own moral house in order.

Now, Jesus uses the metaphor of a fruit tree to convey the same idea of the need for inner change.

“A good tree can’t produce bad fruit, and a bad tree can’t produce good fruit.” – Luke 6:43 NLT

This simple analogy is meant to communicate a much deeper truth concerning the inseparable link between outer conduct and inner character. In his gospel account, Matthew records another occasion where Jesus used this same imagery to address the Pharisees, who had just accused Him of casting out demons by the power of Satan.

“A tree is identified by its fruit. If a tree is good, its fruit will be good. If a tree is bad, its fruit will be bad. You brood of snakes! How could evil men like you speak what is good and right? For whatever is in your heart determines what you say. A good person produces good things from the treasury of a good heart, and an evil person produces evil things from the treasury of an evil heart.” – Matthew 12:33-35 NLT

Jesus exposed these self-righteous Pharisees as “bad” trees that produced unacceptable fruit. They were incapable of producing good fruit because they had evil hearts. In essence, they were plagued by a deadly disease that went from their roots all the way to their fruit. It was all-pervasive and rendered everything about them unacceptable and unprofitable.

The lesson is a simple one: Good fruit cannot come from a bad tree. But the implications of this simple illustration are profound. Jesus is telling His disciples that it is the inner character that determines the quality or acceptability of one’s outer conduct. A diseased tree may produce fruit that looks good and appears edible, but that fruit will be contaminated and rendered useless. That’s why Jesus said it is impossible for a bad tree to produce good fruit.

And just to make sure that His disciples understood the analogy, Jesus explained the connection between fruit and followers.

“A good person produces good things from the treasury of a good heart, and an evil person produces evil things from the treasury of an evil heart.” – Luke 6:45 NLT

It all starts on the inside. Or, as Jesus put it, “What you say flows from what is in your heart” (Luke 6:45 NLT). Speech is a byproduct of the heart. So is behavior. Our words and works are the fruit that our lives produce, and if our heart is diseased, we will produce unacceptable fruit. It may look good, but it will be contaminated by the evil intent of a wicked heart. As the prophet Isaiah put it, we are “all infected and impure with sin. When we display our righteous deeds, they are nothing but filthy rags” (Isaiah 64:6 NLT).

Jesus makes it perfectly clear that the condition of a tree can be judged by the quality of its fruit. So, in other words, the true state of a man’s heart can be measured by his conduct. Just as one would never expect a thornbush to produce figs, so we should not expect righteous behavior from a person with an evil heart. And Jesus would later expand on this idea, providing His disciples with a list of the contaminated “fruit” that flows from a diseased heart.

“…the words you speak come from the heart—that’s what defiles you. For from the heart come evil thoughts, murder, adultery, all sexual immorality, theft, lying, and slander. These are what defile you.” – Matthew 15:18-20 NLT

At this point in their relationship with Jesus, the 12 disciples were all “bad” trees. Yes, they had chosen to follow Jesus, but they were not yet filled with the Holy Spirit. It would be three years before Jesus paid the price for their sins by dying in their place on the cross. His death, burial, and resurrection were future events that would provide the means for their inner heart change. But for now, they remained just as they were when Jesus called them: Dead in their trespasses and sins, condemned, unclean, and in need of the life-transforming, heart-restoring, and soul-sanctifying gift of God’s grace made possible through the sacrificial death of His Son.

Jesus knows these men desperately want to believe that He is their Messiah and Lord. But He also knows that they are going to have a difficult time accepting and going what He has said because they lack the necessary power to pull it off. He even seems to challenge their willingness to obey His teaching when He says, “why do you keep calling me ‘Lord, Lord!’ when you don’t do what I say?” (Luke 6:46 NLT). They haven’t even had time to put any of Jesus’ words into action, and yet He knows they are already questioning the validity and feasibility of His words. It all sounds impossible to them. But Jesus wants them to know how just vital it will be that they obey His commands.

“I will show you what it’s like when someone comes to me, listens to my teaching, and then follows it.” – Luke 6:47 NLT

And He provides them with yet another illustration designed to explain the importance of trusting His words even when they can’t fully understand them. They are just beginning their relationship with Jesus and the days ahead are going to be a roller-coaster ride that will test their faith, challenge their loyalty, and disrupt all their preconceived notions regarding the Messiah and His Kingdom. But Jesus wants them to know that if they listen and obey what He has to say, they will one day discover the life-saving nature of His words. Jesus describes it as a man who builds the foundation of his house on solid rock. He takes the time and effort to dig deep and secure the future state of his home, not knowing what the days ahead have in store. But Jesus assures them that their efforts to trust Him will prove profitable.

“When the floodwaters rise and break against that house, it stands firm because it is well built.” – Luke 6:48 NLT

These men have no idea what storms lie in their path, either literally or figuratively. But if they will simply trust what Jesus is telling them and place their hope in the rock-solid nature of His word, they will not be disappointed when the weather of life takes a turn for the worse. And that day is coming.

English Standard Version (ESV) The Holy Bible, English Standard Version. ESV® Permanent Text Edition® (2016). Copyright © 2001 by Crossway Bibles, a publishing ministry of Good News Publishers.

New Living Translation (NLT) Holy Bible, New Living Translation, copyright © 1996, 2004, 2015 by Tyndale House Foundation. Used by permission of Tyndale House Publishers Inc., Carol Stream, Illinois 60188. All rights reserved.

The Message (MSG)Copyright © 1993, 1994, 1995, 1996, 2000, 2001, 2002 by Eugene H. Peterson