One of my favorite poems is only four lines long:

The soul is measured by its flights,
Some low and others high.
The heart is known by its delights,
And pleasures never lie. (The Pleasures of God, 4)

For me, the last line is the zinger: pleasures never lie. It has stuck in my brain for over two decades. Like a sharp knife, it cuts through a lot of my baloney and gets right to the heart of the matter: what matters to my heart.

“Pleasures never lie” doesn’t mean the things we find pleasurable are never deceitful. Many are (Hebrews 11:25), as we all know by lots of personal experience. Rather, it means that pleasure is the whistle-blower of the heart. Pleasure is our heart’s way of telling us where our treasure really lies (Matthew 6:21). When something evil gives us pleasure, we don’t have a pleasure problem; we have a treasure problem. The pleasure gauge is working as designed. What’s wrong is what our heart loves. And pleasure is blowing the whistle. We can lie with our lips about what we love. But pleasures never lie.

And the thing about our pleasure-giving treasures, whether good or evil, is that we can’t keep them hidden, at least not for long. What we truly love can’t help but work its way out of the unseen heart into the plain view of what we do and don’t do, say and don’t say.

This is why Jesus told us that when discerning whether a professing believer is true or false, we must examine their fruit.

Fruit Trees Never Lie

Fruit is one of God’s favorite metaphors for describing what our lives organically produce based on what our hearts believe and love. He employs it repeatedly in the Bible (Psalm 1:3; Proverbs 14:14; Isaiah 3:10; Jeremiah 17:10; Matthew 3:8; John 15:8; Galatians 5:22–23). And to our point, this parable of Jesus is particularly incisive:

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. (Matthew 7:15–20)

This is a devastatingly simple assessment process. We recognize who’s true and who’s false “by their fruits,” what they do and don’t do, what they say and don’t say. A thornbush can insist it’s a vine, but if it bears no grapes, well. . . . A diseased tree might insist it’s healthy, but if the fruit is diseased, well. . . . Out of the abundance of the heart the mouth speaks and the behaviors behave (Luke 6:45). We can lie with our lips about what we love, but fruit trees never lie.

This is meant to be unnerving. Faith, not fruit, is the instrument by which we are saved (Ephesians 2:8). But faith is revealed by fruit. No fruit, no faith (James 2:17). Bad fruit, bad tree (Matthew 12:33). God sees faith in the heart (1 Samuel 16:7; Acts 1:24). But we can see only the fruit of faith. That’s why Jesus said, “You will recognize them by their fruits.”

Trees Take Time to Grow

False brothers and sisters have been a heartbreaking scourge on the church since its very beginning, when Judas joined the band of disciples as a “devil” among saints (John 6:70–71). When the net of the kingdom is cast into the sea of the world, it hauls in both good and bad fish, which must be separated later (Matthew 13:47–50). When the seed of the kingdom is sown into the field of the world, the enemy sows his own seed in the field, causing the devil’s weeds to grow alongside God’s wheat, and must be separated later (Matthew 13:36–43).

That last parable in particular illustrates a difficult reality for us: it often takes a while until we can tell the difference between God’s wheat and the devil’s weeds. The Greek word translated into English as weed in this parable is zizanion, which the original readers likely would have understood to be a particular weed called darnel. Darnel has been known as wheat’s “evil twin” for thousands of years because in seed form and early development it looks very much like wheat, but it’s toxic to humans and so must be separated at harvest.

So when Jesus says, “You will recognize them by their fruits,” he means we will recognize true and false brothers and sisters when they reach a certain level of maturity and their fruit (whether wheat or darnel) can be seen. Judas, Ananias and Sapphira, and Simon the magician all looked like wheat to the disciples at first (Acts 5:1–11; 8:9–24). Until the toxic fruit of their falseness became visible.

What makes this whole process even trickier is that good trees sometimes act sinfully and bear bad fruit. There’s Aaron and the golden calf (Exodus 32:1–6), David and Bathsheba (2 Samuel 11:1–25), Peter denying Jesus (John 18:15–18, 25–27), Peter and Barnabas acting hypocritically (Galatians 2:11–13), a number of Corinthians acting pridefully, immorally, suing each other, and engaging in various other sins (1 Corinthians 4:8; 5:1; 6:1–8; 8:1). Those don’t look like good fruits. So were they bad trees?

No and not necessarily (since I can’t vouch for all the nameless Corinthians). Why? Because when confronted, they “[bore] fruit in keeping with repentance” (Matthew 3:8). And the bad fruit proved to be an anomaly in a longer-term context of bearing good fruits.

Testing Fruit Quality

In the new covenant age, this is where church discipline becomes crucial. In Matthew 18:15, the brother who, when confronted with his fault, listens and truly repents is to be considered a true brother — a “good tree” — even though he had a “bad fruit” episode. But a “brother” who refuses to listen, even when repeatedly confronted in the context of the covenant community of a local church, is to be considered an unbeliever — a “bad tree” — because his bad fruit appears to be normalizing sin rather than being an anomaly (Matthew 18:16–17).

This church discipline doesn’t determine the nature of the tree; only God does that. Paul clearly hopes the excommunication of an immoral Corinthian church member becomes a means of his repentance and salvation (1 Corinthians 5:5). But since we can only assess a tree by its fruit, we must call it as we see it. And if severe discipline results in repentance, proving the tree is good after all, we will overflow in joy.

In testing the fruit quality of a person, we are very rarely expected to make such an assessment on our own. That’s dicey business, since we have such a tendency to minimize our log and magnify another’s speck (Matthew 7:3). This assessment is meant to take place in the context of a church (1 Corinthians 5:11–13), where our limited perceptions and particular experiential and temperamental biases can be mitigated by a wider group led by mature, judicious elders.

We’re also called to assess our own fruit quality (2 Corinthians 13:5). But I would say that, just as we should not assess others’ fruit in isolation, we should not assess our own in isolation. Our pride distorts our self-assessments in both exalting and condemning ways. The brothers and sisters who observe us most and know us best typically have a more judicious evaluation of us than we do. We need their encouragement and exhortations to help us stay aware of sin’s deceitfulness (Hebrews 3:12–13). And our willingness to receive their observations and repent when necessary is a sign of a good tree — repentance is itself good fruit.

And fruit — consistent fruit over time — is what confirms the species of a tree. Pleasures — consistent, controlling pleasures over time — never lie. These pleasures always work their way out of our hearts into external pursuits — our words and deeds that reveal what we treasure. Jesus calls these “fruits.” They are the only way the church or the world can tell a real Christian from a false one. Which is why Jesus said, “By this my Father is glorified, that you bear much fruit and so prove to be my disciples” (John 15:8).