Matthew 5:17-20: Jesus Fulfills the Law

Introduction

Imagine for a moment that you want to build a house. The first thing you do is consult the plans. You ask an architect to draw the foundation, the walls, the roof. Those plans are essential. But can you live in the plans? Can you take shelter under a sheet of paper when it rains? Of course not. The plan announces the house, it defines it, but the plan is not the house.

In the passage from Matthew we're about to read, Jesus is talking about exactly this difference: the difference between the plan and the reality, between religious rules and a truly transformed life. We're in the heart of the Sermon on the Mount, and Jesus is building something. He doesn't start by handing you a list of things to do. He calls you to a radical righteousness, a righteousness that flows from a living union with him.

This Sunday, February 8, 2026, at Efficient Church, Hugues Wessel continued his series on the Sermon on the Mount. After the Beatitudes and the result of the Beatitudes (salt and light), he invites you today to consider Jesus' call to a righteousness that surpasses that of the scribes and Pharisees: Matthew 5:17-20.

Sermon Outline

1. Jesus doesn't abolish the Law, he fulfills it

"Don't think that I came to destroy the law or the prophets. I didn't come to destroy, but to fulfill" (Matthew 5:17). Some, reading Jesus, may have hoped he'd finally do away with the strict rules. But Jesus stops them right there. God's word doesn't change. Not one letter, not the smallest stroke of a pen, will disappear until everything has come to pass.

You might then imagine that Jesus is simply more demanding, that he's come to give us a higher law, an even harder moral standard to reach. That's not it. Jesus isn't just the one who shows us how to live. He's the one in whom God now looks at us differently, through our union with Christ.

2. Fulfill: the Greek word that changes everything

What does fulfill mean? The Greek word Matthew uses means to fill up, to bring to completion, to give full meaning. Let's go back to the image we started with. The Old Testament, the Law, the rituals, the sacrifices: all of that was the architect's plan. It was true, it was divine. But it was the picture of what was still to come.

When Jesus arrives, he doesn't tear up the plan. He builds the house. He makes real everything the plan pointed to.

• The Law called for a spotless, unblemished lamb for forgiveness. Jesus is the Lamb of God.
• The Law called for a temple to meet with God. Jesus is that Temple, bringing God's presence among us.
• The Law called for perfect obedience. Jesus is the only man who ever loved God with all his heart, all his soul, and his whole life, without ever failing.

Picture a graft. An ordinary apple tree grafted onto a noble branch. This isn't just a cosmetic touch-up. The trunk and roots now receive the taste, the qualities, and the nature of the noble fruit. In the same way, your union with Christ doesn't mean slapping a religious coat of varnish over your old heart. It's a graft that produces new fruit in you.

Jesus didn't come to lower the bar of God's holiness so you could reach it more easily. He came to embody that holiness. He tells you: "I'm the target that the whole story of the Bible has been aiming its arrow at."

3. A righteousness greater than that of the Pharisees

Here Jesus drops what feels like a bomb in the middle of the crowd: "For I tell you that unless your righteousness exceeds that of the scribes and Pharisees, there is no way you will enter into the Kingdom of Heaven" (Matthew 5:20).

For you today, "Pharisee" is an insult. We call a hypocrite "pharisaical." But in Jesus' day, the Pharisees were the heroes of the faith among God's people. They were committed, they knew their Bible, they knew the rules, and they practiced them. At the Winter Olympics of spirituality, they'd have been gold-medal athletes across the board: praying three times a day, fasting twice a week, knowing Scripture by heart, giving generously.

And who is Jesus saying this to? Fishermen, farmers, ordinary people. You can imagine the discouragement: "Lord, that's impossible. I don't have the time, I'm exhausted, I don't have the discipline, I don't have the knowledge. Do better than a Pharisee?"

4. Pharisaic righteousness: a visible performance

To understand what Jesus is asking, you first need to understand what the Pharisees' righteousness actually was. It was a righteousness of management, something measurable: "I took my steps, I said my prayers, I paid my tithe." A visible righteousness, seen from the outside. In a word: a performance.

Imagine a machine that breaks down. Instead of replacing the broken part, you jury-rig something. The machine seems to work again. But it's dangerous, because the fix is only surface-deep. That surface fix looks like the real thing: visible, functional, but dangerously insufficient.

Jesus even uses a harsh image in Matthew 23: the Pharisees clean the outside of the cup, but the inside is full of filth. Pharisaic righteousness is repainting the front of a house that's crumbling inside. It's spraying perfume on a body that hasn't been washed. Socially acceptable, religiously impressive. But to God, who looks at the heart, not enough.

5. Jesus' righteousness: quality, not quantity

So how can your righteousness surpass theirs? Jesus isn't asking you to do more. He's asking you to be true. It's a call to a righteousness of an entirely different kind.

In the verses that follow, Jesus illustrates this six times: "You have heard that it was said... but I tell you." Let's look at two examples.

• Murder. Pharisaic righteousness says: "I haven't stuck a knife in anyone's stomach this week, so I'm righteous." The bar is set at the level of the physical act. But Jesus asks: "Have you nursed hatred against your brother? Bitterness, resentment? Have you called him a fool in the privacy of your own thoughts?" Jesus looks at the root.
• Adultery. The Pharisee will say: "I haven't slept with my neighbor's wife, so I'm in the clear." But Jesus asks: "What have you done with your eyes? What have you cultivated in your imagination, in the secrecy of your heart?"

The righteousness of the scribes and Pharisees was a way of managing behavior. The righteousness of the Kingdom transforms your deepest desires. Human righteousness stops at the visible act. God's righteousness reaches all the way down to the heart.

Another picture: a bandage covering a wound. A bandage can't stop an infection. You have to clean the wound, treat it, heal it at the root, and only then protect it. Jesus isn't a bandage. He wants to reach the root, not just cover up the symptom.

6. Two wrong answers: legalism and antinomianism

Faced with this demand, you might feel uneasy. You might say: "If that's how it is, who can be saved? I can control my hands, my actions, I can force myself to smile. But I can't control the movements of my heart. I can't keep myself from being jealous, angry, or having impure thoughts by sheer willpower."

That's exactly where Jesus wants to lead you. Throughout history, humanity has given two wrong answers to this problem:

1. Legalism. Trying by your own strength. Gritting your teeth, putting on a mask, becoming harsh with yourself and with others. In the end, you're just play-acting, like the Pharisees.
2. Antinomianism. Rejecting every rule. "It's impossible, so never mind, God is love, he'll forgive me, there's nothing for me to do." Grace becomes an excuse not to change.

Both answers are dead ends. The Old Testament shows us God's holiness, but it doesn't give us the strength to reach it. The Law is like a mirror: a mirror can show you that your face is dirty, that your hair is a mess, but it can't wash you or comb your hair. The Holy Spirit, on the other hand, is like the water that actually makes you clean.

7. The promise of a new heart

Jesus didn't come only to hand out difficult commands. He came to inaugurate the new covenant. Remember the promise through the prophet Ezekiel: "I will give you a new heart, and I will put a new spirit within you. I will take away the stony heart out of your flesh, and I will give you a heart of flesh" (Ezekiel 36:26).

Your entrance into the Kingdom doesn't rest on what you produce, but on Christ and what he has accomplished. It's the work of the Holy Spirit that granted you poverty of spirit and hunger for God's righteousness. It's the work of the Holy Spirit that bears fruit in your sanctification. This righteousness that surpasses that of the Pharisees isn't a righteousness you manufacture: it's a righteousness you receive.

When you're in Christ, your tastes start to change, along with your desires and your reactions. Christians who've walked with the Lord a long time see it over time: their desires are no longer the same. It's not a choice they made; it's the work of the Holy Spirit. What was, at first, an outward constraint gradually becomes an inward life. You no longer forgive because you have to, but because Christ's life in you pushes you toward grace. You no longer flee impurity out of fear of punishment, but because your new heart is beginning to love purity.

Key Takeaways

• Jesus doesn't abolish the Law: he fulfills it. He's the actual house that the Law was only the plan for.
• Kingdom righteousness isn't a matter of quantity (doing more) but of quality (being true all the way to the heart).
• The two dead ends when facing the Law are legalism (gritting your teeth) and antinomianism (rejecting every rule).
• The Law is a mirror that reveals the dirt; only the Holy Spirit can clean it.
• The righteousness that gets you into the Kingdom is a righteousness received in Christ, not one manufactured by your own efforts.

Personal Application

• Am I living out my faith as a visible performance, or as an inward graft?
• What root, hidden behind acceptable behavior, does the Holy Spirit want to address in my heart this week?
• Do I lean more toward legalism (gritting my teeth) or antinomianism (treating God's holiness as no big deal)?
• Am I trying to look like a Christian, or am I letting myself be transformed by Christ?
• When I come to the Lord's Table, am I coming to find the strength to become righteous, or am I celebrating the fact that I'm already united with Christ?

Verses Cited

• Matthew 5:17-20 — Jesus, the Law, and the righteousness of the Kingdom
• Matthew 5:17 — Not to destroy but to fulfill
• Matthew 5:20 — A righteousness greater than that of the Pharisees
• Matthew 23:25-26 — The outside of the cup and the inside
• Ezekiel 36:26 — The new heart and the new spirit

FAQ

What does Jesus mean when he says he came to "fulfill" the Law?

The Greek verb translated "fulfill" means to fill up, to bring to completion, to give full meaning. Jesus doesn't do away with the Law, and he doesn't weaken it either. He makes real what the Law and the prophets pointed to. The Law was the architect's plan: Jesus builds the house. The spotless lamb, the temple, perfect obedience: all of it takes concrete shape in him.

How can my righteousness surpass that of the Pharisees if they were already "spiritual athletes"?

Jesus isn't asking you to pile more performance on top of their performance. He completely shifts the ground under the question. Their righteousness was a visible management of outward behavior. The righteousness he calls for is an inward transformation of your desires and your heart. It isn't manufactured, it's received through union with Christ. It's not "more," it's "different."

How do I avoid both legalism and spiritual laxity?

Both extremes share the same mistake: they treat the Law as something you either have to carry by your own strength (legalism) or as something that no longer matters (antinomianism). The answer lies elsewhere: recognize with Jesus that your righteousness falls short, let the Holy Spirit give you a new heart, and let Christ live in you. Then obedience stops being a burden and becomes the natural fruit of a life grafted onto his.