Murder in the Heart
Matt. 5:21–26 – Living in the Kingdom: The Sermon on the Mount – Daniel J. Baker – Aug 10, 2025

Introduction

“If you’re able, please stand.” Reading Matt. 5:17–26. “Thanks be to God.”

Anger and sports go together. It's amazing what happens as soon as you start keeping score! E.g., my days on my club soccer team. Totally random rivalries: Roswell? And then I got saved! And everything changed...sort of. My sinful anger didn't. But then I got older and had children and everything changed...sort of. Now my sinful anger wasn't about MY experience on the field, but how my children's team was fairing. The refs!

My anger wasn't murder. But Jesus tells me that my anger at those times is worthy of the fires of hell. 

This morning we’re in Matthew 5, which is part of what’s been called “the Sermon on the Mount.” And that’s because of the detail in Matt. 5:1 that Jesus “went up on the mountain” to give this sermon. Matthew’s gospel is organized with 5 big blocks of Jesus’s teaching (5–7, 10, 13, 18, 24–25). So, we’re in the first big section of his gospel.

The theme of “the kingdom of God” has been emphasized already in the early chapters of the gospel. You can see this in the summary of Jesus’s message when he began preaching:

From that time Jesus began to preach, saying, “Repent, for the kingdom of heaven is at hand.” (Matt 4:17)

So when we get to the Sermon on the Mount we’re not surprised by the references to “the kingdom of heaven” (equivalent to “kingdom of God,” 6:33) in 5:3, 10, 20; 6:33; 7:21.

What we get in the Sermon in the Mount is teaching on “Living in the Kingdom.” For those who believe in Jesus and living under “the reign of God” (that’s what the kingdom is), how should we live? That’s what Jesus is giving us.

Today Jesus will teach us that “living in the kingdom” requires that we put our sinful anger to death. Anger is like murder in the heart.

A quick review from last week on Jesus “fulfilling” “the Law and the Prophets” (Matt 5:17). Jesus’s life, death, and resurrection changed how God’s people are to relate to the Law of Moses. Jesus and the apostles have a way of handling the Old Testament laws that has been summarized as dividing them into three types of laws: Moral, Ceremonial, and Civil.

First, Moral laws: Moral laws are Old Testament laws that relate to how we are to love God and love our neighbor (Matt 22:37–40). Jesus “fulfilled” them by obeying them (Matt 3:15), and we are to “fulfill” them also by obeying them—through Christ and by faith (Rom 13:8–10).

What Jesus is talking about in the Sermon on the Mount, especially in Matt. 5:21–48, connects to the moral laws of the Old Testament. All these examples where Jesus says, “You have heard it said,” connect to the moral laws. None of these have been “fulfilled” so that we no longer need obey them. But Jesus has much to teach us about HOW we obey them.

Second, Ceremonial laws: Ceremonial laws are Old Testament laws connected to the sacrifices for sin in the Old Testament and laws about being “clean” and “unclean,” laws about the priesthood. Jesus “fulfills” these laws once and for all through his crucifixion. See Hebrews 10:14, 18.

Hebrews 10:14, 18:

For by a single offering he has perfected for all time those who are being sanctified....Where there is forgiveness of these, there is no longer any offering for sin. (Heb 10:14, 18)

Third, Civil laws: Civil laws are Old Testament laws that center on the Israelites living together as a political nation occupying a specific piece of land, “the land of Canaan.” Jesus radically changes how we think of these laws by transforming what it means to be “the people of God.” The church as the church is not a political or geographic body. See 1 Corinthians 5:11–13.

1 Cor 5:

But now I am writing to you not to associate with anyone who bears the name of brother if he is guilty of sexual immorality or greed, or is an idolater, reviler, drunkard, or swindler—not even to eat with such a one. ¹² For what have I to do with judging outsiders? Is it not those inside the church whom you are to judge? ¹³ God judges those outside. “Purge the evil person from among you.” (1 Cor 5:11–13)

The important thing to see here is the punishment. The sins are serious. In the Old Testament, a person guilty of these sins would often be killed. And that’s the context of that quote at the end: “Purge the evil person from among you.” But now in the church, “purging the evil” is done through church discipline—not capital punishment. A government might choose to to make these capital crimes. But the point is, the people of God as the church are no longer a political nation.

This became true at the cross of Christ. At that point the gospel became global. Now all nations who believe in Jesus are part of “the chosen people” (1 Peter 2:10), and the church can be found anywhere on earth where his people are.

What he’s doing in Matthew 5 is giving us the correct reading of these moral laws.

Prayer – Young adults camping/YA Ministry. Crossay (Lancaster)—BT visiting.

I. Murder (5:21)

We start with verse 21. Read Matt. 5:21.

This is the first of a pattern in this Sermon where Jesus says, “You have heard.... But I say....” Sometimes these are called The Antitheses (Matt 5:21–48), because two things are being pitted against each other.

But a key idea here is that what Jesus is giving us is not an interpretation that is inconsistent with the Old Testament. It is a reading that takes into account the whole Old Testament and not just isolated passages.

He is challenging a common interpretation of certain laws, but that interpretation gets off track because it treats laws in isolation and not by seeing all that God has said to his people.

Jesus is not doing away with these moral laws. He’s giving us the right interpretation of them.

We all have a tendency to separate the commandments of God into the “big and serious” ones or into “smaller and less serious.”

A lot of times OTHER PEOPLE are guilty of “big and serious” sins, but WE’RE only guilty of “smaller and less serious” sins.

Jesus starts with “murder.” He assumes that his audience knows murder is wrong and “liable to judgment,” conviction in the Sanhedrin, and the fires of hell, all things mentioned in this verse.

But our day is a different day. Not everything can be assumed. So, let’s lay out some basics on murder.

Jesus quotes from the 6^th commandment, “You shall not murder.” And this is a commandment that gets a lot of attention in the Old Testament, because in a nation like Israel with 2 million people, there are a lot of ways a person might be responsible for the death of another person.

• Murder is the sinful taking of a life. Exod 20:13.
• Different than simply “killing,” which might happen in a just war or by a governmental act to punish a crime. “He does not bear the sword in vain” but is called “an avenger who carries out God’s wrath on the wrongdoer” (Rom 13:4).
• Different from “negligent homicide,” where someone does kill someone, but it’s due to negligence and not a premeditated act of sinful taking a life. Still very serious. Exodus 21:28–29: If an ox gores a person to death, you kill the ox. BUT: “If the ox has been accustomed to gore in the past, and its owner has been warned but has not kept it in, and it kills” someone, the ox AND the owner shall be “put to death.”

Murder is premeditated, intentional, and sinful. We get a picture of it in Deuteronomy 19:

“But if anyone hates his neighbor and lies in wait for him and attacks him and strikes him fatally so that he dies...” (Deut 19:11)

Do you see the elements there? “Hates,” “lies in wait,” “strikes him fatally.”

But the sinful taking of a life can happen in a lot of different ways in our day. Of course, criminal murder like we’ve described is one. But also: 

• Abortion as an act of birth control is wrong. It’s the sinful taking of a life, just a very young life.
• The intentional destruction of an embryo related to the process of IVF is wrong.[1] Even the unintentional destruction of an embryo can be seen as a kind of “negligent homicide.”
• Assisted suicide is wrong.
• Euthanasia for the elderly or the extremely sick because they don’t measure up to a standard of “quality of life” we arbitrarily determine is wrong.

John Frame in this context mentions Joni Eareckson Tada, a quadriplegic from the age of 17. Some might argue her “quality of life” was too bleak for her to continue. They might have recommended assisted suicide or euthanasia. And yet, she has ministered to millions of people through her decades of music, writing, and speaking.[2]

“You have heard that it was said to those of old: ‘You shall not murder,’” and Jesus is not rejecting that commandment. He is affirming and assuming it!

But he’s got more to say.

II. Anger (5:22)

Read Matt. 5:22.

Jesus gives us here an escalating series of offenses and responses:

• “angry with his brother” — “liable to judgment”
• “insults” (lit., says Raca, “stupid!”) — “liable to the council” (Sanhedrin)
• “whoever says, ‘You fool!’” (Gr., mōros, word behind our “moron”) — “liable to the hell of fire” (“hell” = “Gehenna,” valley to south of Jerusalem, place where trash was thrown)

The escalation starts with anger. That anger might not be expressed at all, but it’s there and it’s sinful anger.

But at some point, our anger wants to spill over into action:

“Out of the abundance of the heart the mouth speaks” (Matt 12:34)

Our mouth starts speaking. First, “Raca!” The Greek for “whoever insults.” “Stupid!” And the anger builds, and we keep speaking, “You fool!”

Now, there’s way to say these words without any anger. “It’s foolish to have too big a car loan when you don’t have much income.” But Jesus isn’t talking about those times. He’s talking about times we say these words are spoken from an angry heart.

We haven’t murdered the person...YET! But we have an angry heart, and we’ve spoken angry words.

But, of course, sometimes “out of the abundance of the heart the mouth doesn’t say anything at all.” Silent, brooding anger is the heart expressing itself just as much as screaming.

Jesus isn’t telling us here that anger and angry words are EQUAL to murder. He’s telling us that they are FAR MORE EVIL than we typically think.

Jerry Bridges wrote a book to drill down into that tendency of ours: Respectable Sins. He says in the preface,

The motivation for this book stems from a growing conviction that those of us whom I call conservative evangelicals may have become so preoccupied with some of the major sins of society around us that we have lost sight of the need to deal with our own more “refined” or subtle sins.
Jerry Bridges, Respectable Sins[3]

That’s really what Jesus is doing, looking at what we might call “Respectable Sins” and showing us they’re evil and sinful. These three sins don’t offend our sensibilities in the same way murder does, but that’s because of our flawed morality and not the sins themselves.

Sinful anger has the same DNA as murder. It comes from the same heart, the same stuff as premeditated murder.

The difference is how far we go with it.

By condemning anger, Jesus is not teaching anything here that is contrary to God’s law. God’s law from the time of Moses condemned sinful anger.

See this in Leviticus 19:17:

“You shall not hate your brother in your heart, but you shall reason frankly with your neighbor, lest you incur sin because of him.” (Lev 19:17)

Murder is condemned in God’s law, but so is “hating your brother in your heart.”

We need to think a bit about what makes anger anger.

Anger always includes a judgment. You have evaluated someone and judged him to be deficient in some way. And his failure is so serious that anger is the only proper response.

David Powlison

At its core anger is very simple. It expresses “I’m against that.” It is an active stance you take to oppose something that you assess as both important and wrong. You notice something, size it up, and say, “That matters...and it’s not right.” You encounter something in your world that crosses the line. Anger expresses the energy of your reaction to something you find offensive and wish to eliminate.
David Powlison, Good & Angry[4]

Sometimes we talk about “righteous anger” and “sinful anger.” They’re both anger, but one is right and the other is wrong.

In both cases you are making a judgment and responding.

Righteous anger can become sinful anger in two ways. One way is that OUR JUDGMENT IS WRONG. We determined something to be “offensive” and “wrong” and “crossing the line,” but we’re just wrong.

Parening is filled with opportunities to do this.

The second way righteous anger can become sinful anger is that OUR RESPONSE IS TOO BIG.

Maybe a line was crossed. Maybe something offensive did happen. But we totally over-reacted. We screamed and cursed. Or maybe we didn’t talk to the person for 3 days.

We were acting like the person had intentionally just runover his grandmother and fled the scene.

The irony in those times is that our sinful anger is 100 times worse than whatever offense they committed.

But it’s also possible to be sinful by NOT being angry. If righteous anger means you make a right judgment and have a right response, sometimes we fail to honor God by not judging something wrong that is wrong. Or we judge it wrong but it doesn’t really affect us emotionally.

That’s a different kind of failed anger, but it’s still a moral failure.

Dietrich Bonhoeffer:

Every idle word which we think so little of betrays our lack of respect for our neighbour, and shows that we place ourselves on a pinnacle above him and value our own lives higher than his. The angry word [“Fool!”] is a blow struck at our brother, a stab at his heart: it seeks to hit, to hurt, and to destroy. A deliberate insult is even worse, for we are then openly disgracing our brother in the eyes of the world, and causing others to despise him.
Dietrich Bonhoeffer, The Cost of Discipleship[5]

Diagnosing your anger:

• What did you get angry about?
• Why do you get angry about it?
• What was the result of your anger?
• Was anger the right response, and was the amount of anger appropriate?
• How would a right response look like?
• What would be the result if you had acted like that?

III. Reconciliation (5:23–26)

The longest part of this passage is dedicated to reconciliation, teaching us what we are to do if we know that there is a relational break with someone in our life.

Read Matt. 5:23–26.

If anger is a problem in our life, we tend to think of it in very personal terms:

• “I struggle with anger, and I need to work on that.”
• “Can you pray for me, I often get angry with my husband?”

But Jesus is telling us here that our anger is a much bigger deal than just being a personal weakness you need to overcome. It’s connected to every part of your life and it may have major consequences.

Jesus presents two scenarios to make his point. He starts with our worship.

We tend to think of worship as a personal experience. It’s between me and God. It’s all about my heart for him. So, what matters in my worship is how I feel about God in the moment of worship.

But Jesus says, NO. Your worship of God in the temple (i.e., with the gathered church) is connected to everything else in your life—especially your relationships with other people.

So, if you’re making an offering and remember that because of your anger“your brother has something against you,” go and deal with the broken relationship first. And THEN come offer your gift.

“Be reconciled” (from diallassomai[6]) – Work to restore peace between you and “your brother.” One Greek lexicon defines it as, “to change a person from enmity to friendship” (Liddell & Scott). Our anger has made a person to be at “enmity” with us. We are to work to restore “friendship.”

If you’ve tried and it isn’t possible, then you’ve done what you can and should make your offering.

If possible, so far as it depends on you, live peaceably with all. (Rom 12:18)

Remember the context for Jesus’s teaching. The temple is still standing in Jerusalem and that’s where “the altar” would have been. The person in this scenario may have travelled several days to make the offering. But now Jesus is saying to such a person, that you need to leave the gift, go and be reconciled, and THEN offer your gift.[7]

The scenario tells us just how “NECESSARY”[8] it is to be in right relationship with our brothers and sisters in the church. Our Sunday worship cannot cover up a life of being terrible to other people. God sees it all. God wants our worship to be the overflow of a life dedicated to him—not the exception.

In the second scenario, it’s a legal situation. Now it’s “your accuser” and not “your brother”; now you’re on your way “to court” (v. 25), not in church.

Now your anger or slander has provoked someone to sue you. Jesus says here, Don’t add to your troubles by being proud and defiant and over-confident about the legal process. If you continue to be stubborn and proud, you may find yourself on the wrong side of a verdict and end up in jail “until you have paid the last penny” (v. 26).

Jesus is reminding us here that part of God’s work in our lives is to let us experience the consequences of our sins.

Remember Hebrews 12:

And have you forgotten the exhortation that addresses you as sons? “My son, do not regard lightly the discipline of the Lord, nor be weary when reproved by him. ⁶ For the Lord disciplines the one he loves, and chastises every son whom he receives.” ⁷ It is for discipline that you have to endure. God is treating you as sons. For what son is there whom his father does not discipline? (Heb 12:5–7)

Our two scenarios teach things we all know to be true:

• Anger can ruin relationships.
• Anger can have expensive and long-lasting consequences.

Sinclair Ferguson:

The illustration of the man in church underlines the necessity of reconciliation. The illustration of two men going to court underlines the urgency of reconciliation. Animosity is a time bomb; we do not know when it will “go off.” We must deal with it quickly, before the consequences of our bitterness get completely out of control.
Sinclair Ferguson, Kingdom Life in a Fallen World[9]

Conclusion

My sins in sports.

Sinful anger is worthy of the fires of hell. The remedy for us is another great act of reconciliation. Another great act where “enmity” was turned into “friendship.”

It was Jesus Christ through his death who cured God’s enmity against us.

Romans 5:

For if while we were enemies we were reconciled to God by the death of his Son, much more, now that we are reconciled, shall we be saved by his life. (Rom 5:10)

The result if we receive his gift is “peace with God” (Rom 5:1).

No longer enemies! Now we have “peace with God.”

This is his offer of mercy: RECEIVE IT BY FAITH!

An invitation to respond:

• If you battle sinful anger that is affecting your life and relationships.
• Maybe it’s the screaming kind.
• But maybe it’s the brooding, silent kind.
• Either way, it’s affecting your life and relationships.
• After the service, come forward to pray with the prayer team.
• In just a moment, I’ll ask you to raise your hand as we pray.

Prayer: With our eyes closed, please raise your hand if anger is a pronounced issue for you, and you’d like God’s grace to help you repent and change.

Closing Song

[1] See the articles by Wayne Grudem and John Frame: https://www.thegospelcoalition.org/article/ivf-morally-right/, posted April 25, 2019; “The New Reproduction,” https://frame-poythress.org/the-new-reproduction/, posted May 21, 2012. Both posts are excerpts of their respective works on Christian ethics, Grudem’s, Christian Ethics (rev. 2024); and Frame’s, The Doctrine of the Christian Life (2008).

[2] John Frame, The Doctrine of the Christian Life (Phillipsburg, NJ: P&R, 2008), 737.

[3] Jerry Bridges, Respectable Sins (NavPress, 2007), 9.

[4] David Powlison, Good & Angry: Redeeming Anger, Irritation, Complaining, and Bitterness (Greensboro, NC: New Growth, 2016), 39.

[5] Dietrich Bonhoeffer, The Cost of Discipleship (1937 orig.; NY: Colier, 1963), 144.

[6] A word used only here in the NT. The more common words for “reconcile” are related to katallassō, but those words always have to do with being reconciled to God.

[7] Insight on the distances possible is from R.T. France, NICNT, 203.

[8] Sinclair Ferguson, Kingdom Life in a Fallen World, 118.

[9] Sinclair Ferguson, Kingdom Life in a Fallen World (NavPress, 1986), 118.