Text: Matthew 5:33–37
Preacher: Pastor Brian Sauvé
On Pretending to be God
In Matthew 21, Jesus tells a parable of a man who had two sons. And he went to the first one and said, “Son, go and work in the vineyard today.” And the son answered, “I will not,” but then he changed his mind a bit later and he went and worked the vineyard.
And the man went to this other son and said the same thing, “Go work in the vineyard today.” This second son answer eagerly, “Yes sir, I will go.” But a bit later, he changed his mind and did not go. Jesus asks the question, “Which son did the will of his father?”
The answer is plain: The first son, whose words were wrong, but whose works were right, is the one who did his father’s will. Now, the application of the parable that Jesus gives in Matthew 21 is different than what I want to point out—don’t worry, we’ll get there in 2026.
But at the structural core of that parable, the reason it works, is because fundamentally, what you say you will do is far less important than what you actually do. Obviously, what you say you will do isn’t unimportant, but the reason Jesus’ parable works in Matthew 21 is because words, though important, aren’t as important as deeds.
In our text, Matthew 5:33–37, Jesus continues teaching us about the righteousness that will mark his Kingdom—this righteousness that exceeds that of the scribes and the Pharisees—a righteousness that will make the “Yes” and the “No” of the one who gives it of far greater weight than all of the elaborate oaths and vows and incantations sworn on the grave of anyone’s mother.
Look there with me, and we will get his words in front of us, Matthew 5:33–37. This is the Word of the Living God:
“Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform to the Lord what you have sworn.’ But I say to you, Do not take an oath at all, either by heaven, for it is the throne of God, or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. And do not take an oath by your head, for you cannot make one hair white or black. Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil.”
-Matthew 5:33–37
Thus ends the reading of God’s Word; may he write it on our hearts by faith.
The Doctrine: Oaths & Vows
As with the previous sections of the sermon, Jesus is teaching on how to properly obey the Law. When he says, “Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform to the Lord what you have sworn,’” he’s referencing several passages in the Law. I’ll read a few:
“You shall not swear by my name falsely, and so profane the name of your God: I am the LORD.”
-Leviticus 19:12
“If a man vows a vow to the LORD, or swears an oath to bind himself by a pledge, he shall not break his word. He shall do according to all that proceeds out of his mouth.”
-Numbers 30:2
“If you make a vow to the LORD your God, you shall not delay fulfilling it, for the LORD your God will surely require it of you, and you will be guilty of sin. But if you refrain from vowing, you will not be guilty of sin. You shall be careful to do what has passed your lips, for you have voluntarily vowed to the LORD your God what you have promised with your mouth.”
-Deuteronomy 23:21–23
“Guard your steps when you go to the house of God. To draw near to listen is better than to offer the sacrifice of fools, for they do not know that they are doing evil. Be not rash with your mouth, nor let your heart be hasty to utter a word before God, for God is in heaven and you are on earth. Therefore let your words be few. For a dream comes with much business, and a fool’s voice with many words.
When you vow a vow to God, do not delay paying it, for he has no pleasure in fools. Pay what you vow. It is better that you should not vow than that you should vow and not pay. Let not your mouth lead you into sin, and do not say before the messenger that it was a mistake. Why should God be angry at your voice and destroy the work of your hands? For when dreams increase and words grow many, there is vanity; but God is the one you must fear.”
-Ecclesiastes 5:1–7
So these passages clearly teach that you are doing a weighty thing when you make a vow—that God expects you to see it through. So as he has been doing in this section of the sermon on the mount, Jesus would teach us what it would look like for a righteous man to stand in relationship to these laws.
One of my favorite books growing up was The Adventures of Huckleberry Finn by Mark Twain, because of how perfectly it just hilariously captures the heart of boyhood. One scene in particular sheds light on why Jesus had to give this teaching, on what it is that the Pharisees had done to obscure proper obedience to the Law when it came to swearing oaths.
In the story, Huck Finn is forming a gang with some other young boys, Tom Sawyer included, of course. And they’re trying to figure out how to solemnize membership in the gang, and so of course, they have to sign their names in blood and all sorts of other stuff they’ve gotten from novels about pirates and gangs of thieves.
And they decide that each of them has to swear an oath that if they rat out the gang, the other boys are allowed to kill one of their family members. And this introduces a problem for Huck, since he’s an orphan and doesn’t have any family they could kill. But Tom realizes that they could always kill the widow Douglas, who sort of adopted Huck, and then the narrator says something like, “They were all really happy when they realized the widow Douglas would do, because they really liked Huck and wanted him in their gang.”
Little kids do this, right? “Cross my heart and hope to die, stick a needle in my eye.” “I pinky promise.” “I swear on my mother’s grave.”
The Pharisees did as well. They knew that proper oaths were to be sworn in the name of God. And they understood the gravity of those oaths—that to break one was a weighty sin. And as hypocrites and sinners, they wanted to hold onto two things at the same time: They wanted to be able to have the noble appearance of swearing oaths, but they also wanted to be able to freely break those oaths.
So they came up with a workaround, where they would swear on “big” things in God’s name, but then make lesser vows on other things—the Temple, the earth, Jerusalem, the hair of their own heads, etc.
And so Jesus cuts through the superstition and faithlessness of men, and gives us the truth concerning promises, vows, oaths, and our actions surrounding them.
Now, before we unpack that, I want to show you that Jesus isn’t here actually annulling and voiding all oath-taking. Remember the kind of hyperbole that we saw just a few weeks ago about gouging out your eye or cutting off your hand rather than sinning. Hyperbole is a common Jewish linguistic device, where you communicate a truth through extreme language and exaggeration
We shouldn’t take Jesus to mean that all vows and oaths are inherently sinful—that the sin is located in the oath itself—because to do so would be to make the Scriptures contradict each other. The sin doesn’t live in the oath, but elsewhere. Paul took vows, as in Galatians, where he says, “I assure you before God, I am not lying.” Jesus himself takes oaths to keep covenant in Luke 1:73 and Hebrews 6. God swears oaths.
In fact, the entire superstructure of the Scriptures is constructed around covenants, which involve solemn oaths and vow. So what is Jesus teaching us about how to related to oaths and vows? At least four things. First, that…
1. All promises, oaths, vows, etc. are given in God’s very presence—swearing on lesser things isn’t a real loophole.
These superstitious escape hatches didn’t really provide cover for the one making the oath.
Jesus would have us see that swearing on your own head or on the city of Jerusalem is still swearing by God. Why? Because God is the true master of all of those things. They all belong to him. Our every word, and therefore our every oath, is made in God’s presence. He is Lord everywhere and he is present everywhere.
And when we swear falsely in God’s name—even if we thought we were not swearing by God at all—we blaspheme. But working our way even deeper into Jesus’ teaching here, number two:
2. The righteous don’t need oaths.
Not all oaths are sins. Hopefully we established that a moment ago. But remember, Jesus is teaching us how to obey the law properly, from the heart, in its intended fulness. Look again at verse 33,
“Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform to the Lord what you have sworn.’ But I say to you, Do not take an oath at all… Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil.” -Matthew 5:33–34a, 37
The heart of this teaching is unlocked when you understand something fundamental: The righteous don’t need oaths. If you are righteous, as Jesus is, then your “Yes” and your “No” is adequate. Your ‘Yes’ and your ‘No’ is just as binding as an oath sworn by God.
Anything more than this comes from evil, because if nobody was evil, oaths wouldn’t add weight to anyone’s promises. So number three…
3. It’s not what a person swears on that is of central importance, but who it is that is swearing the oath.
A liar swears by God himself and yet fails to keep the oath, while a faithful man simply gives his “Yes,” and keeps it without invoking God or gold or his mother’s grave.
The nature of the person giving their word is the most important feature, not elaborate oaths. Jesus’ Kingdom, since it is a Kingdom whose righteousness exceeds that of the scribes and the Pharisees, is one wherein its citizens don’t need oaths. They have Yes and they have No, and that is enough.
Remember the two sons of the parable: The location of sin and righteousness in relationship to oaths isn’t first in the words and the oaths, but in the doing of what was said. Words, though important, aren’t as important as deeds. Deeds without words are great. Words without deeds are damnable.
Finally, number four, Jesus rebukes this kind of spurious oath-taking, because:
4. Oaths can function as claims to sovereignty.
We could say that making oaths in a certain way is a claim to deity. He says,
“Do not take an oath at all, either by heaven, for it is the throne of God, or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. And do not take an oath by your head, for you cannot make one hair white or black.”
Do you see what I mean? You can’t make one hair white or black. Jerusalem isn’t your city. The throne of God is God’s. The earth is his footstool. Can you swear by these that you don’t own? No! You’re not the Lord of them! To swear by them is to claim sovereignty over them.
Later in the sermon, Jesus rebukes unrighteous anxiety in a similar way. He says, “And which of you by being anxious can add a single hour to his span of life?” Anxiety is acting like you are in charge of the universe. So is oath-swearing. We might say, “Which of you by swearing an oath can guarantee that you will perform that oath?”
Saying, “I will do x, y, or z” is saying that you can do that. But can you? Are you sure you won’t die in 10 seconds? Are you God? No. See why this is serious? Not only are we blaspheming when we swear and fail to uphold our word, since all oaths are fundamentally in God’s name, since they are given in his presence, but we are also blaspheming when we vow as if we are gods, able to impose our own will on the future.
So rather say something like—and please permit me a Lord of the Rings reference—Aragorn does in The Fellowship of the Ring as he takes the hobbits under his protection, ““I am Aragorn son of Arathorn; and if by life or death I can save you, I will.”
He says, basically “If I can do this, I will.” This is why we should be a people who often say the phrase “Lord willing.” We’re admitting that we are not God, and that God may will differently than we intend, even if our intention isn’t sinful.
The Rise & Fall of Kingdoms
Now, this whole sermon is “Kingdom” talk. It’s about the tenor and tone and culture and righteousness that is to infuse a Kingdom, the Kingdom of God’s Beloved Son. Every element of this sermon is aimed at setting the culture that is to overflow out of the worship and works of this people whom Jesus came to save by means of this death, burial, and resurrection.
So think about what happens when this teaching is neglected in a Kingdom, in a culture, when our yes isn’t yes and our no isn’t no, and so we have to make up for our faithlessness with bluster and solemn oaths and the multiplying of words and ceremonies.
That is the death of a culture. When faithfulness dies, so does a culture. When you can’t trust your neighbor, your mechanic, your coworker, your spouse—no amount of pretty words will help you.
Truthfulness, faithfulness, is the difference between a kingdom standing or falling. This is one reason that the culture of the kingdom of darkness is a culture of death—it’s a culture built on lies and faithlessness and the absolute and utter incapability of keeping its word.
So the question we ought to ask is simply: What should we do in response to this instruction of our Lord? What should be true of Refuge Church in light of Jesus’ teaching to us? What is to be the tenor of this outpost of Christ’s Kingdom in light of this teaching?
1. There should be a thoroughgoing tenor, a tone in the air, an overwhelming awareness, of our own ungodness at Refuge Church.
We aren’t God. That should show up in our overall self-awareness. It should be plain in our words and our promises that we don’t think of ourselves more highly than we ought, but with accuracy, with humility, with creaturely dependance on the Lord.
When we speak and promise and commit, it shouldn’t sound like we think we are gods. It should rather sound like we are a people deeply aware of our own un-sovereignty, our own ungodness, our own limitations and reliance on the grace, the strength, the providence of God.
2. There should be a pause before promising and a care with words.
Proverbs 10:19 is true,
“When words are many, transgression is not lacking,
but whoever restrains his lips is prudent.”
-Proverbs 10:19
Or as Solomon wrote in the passage of Ecclesiastes we read earlier, “It is better that you should not vow than that you should vow and not pay. Let not your mouth lead you into sin..”
Our culture is careless with words. It misuses them, abuses them, multiplies them, sins with them, tears down with them, lies with them, manipulates with them.
Our culture loves to erase entries in the dictionary and colonize them with sin—defining good as evil and evil as good. Our culture has little care for true, plain, direct speech, and for simple faithfulness in performing our yes and our no.
In the Kingdom we have been welcomed into, this people whom God is raising up, whose righteousness exceeds the Scribes and Pharisees, ought certainly to exceed our cultural carelessness for words. May we pause before we promise and make sure we can perform. May we not promise as if we were gods. May we take care with our speech.
I was thinking about all the ways this can go wrong—just little ways, but little ways that can add up to devastation. Like, I think about my own day to day as a husband and a father. It’s easy to cover up faithlessness under an avalanche of promises and words. “I’ll take you to the park later. I’ll be home by 5:00. I’ll do that tomorrow.” Will I? Do I do what I tell my kids I will? My wife? This is simple, blue collar stuff. And in that same vein, the third way this teaching should mark is is that:
3. Our speech ought to be plain, direct, and truthful.
Jesus doesn’t seem to be very impressed with elaborately ornate words. He doesn’t seem to be impressed by human speeches. He doesn’t seem to weigh the value of our words by volume.
One of the ways we set a guard at our lips and a watch over our own tongues is to seek to speak directly, plainly, and truthfully. Truth and lies are often obscured in indirectness, passive-aggressiveness, passivity, and euphemism. When someone asks us a question that we want to say ‘No’ to, we should say ‘No,’ not, ‘I’ll check my calendar and get back to you.’
4. There should be an eagerness to perform our word.
We are to be a people whose works speak in harmony with our words, but also whose words are less numerous than our works.
Think about how this spirit of plain and truthful speech, eagerly performed, would leaven every aspect of the culture we produce as the people of Refuge Church. Remember, we are a little city on a hill. We are salt and light. Think about how this little outpost of Christ’s universal Kingdom might powerfully bear witness to the goodness of that Kingdom in ten-million little acts of plain, direct, truthful speech.
How would it effect the reputation of Christ in our workplaces? If our yes and no is keen and sharp-edged and true?
How would it effect the business we start and run in our community? How might an honest Christian general contractor that leaven the culture? An honest Christian mechanic?
One failed promise can destroy our reputation and bring reproach to Jesus’ name. But the inverse is also powerfully true: A local church known for its direct, plain, truthful speech and faithful character adorns the name of Christ.
His Yes is Yes, Indeed
Now, I imagine that the law is doing what the law does: Expose our inadequacy, our sin, and our failure. How many of you have sinned against this passage this very week, and didn’t even know it until this morning? You are in good company.
The law is intended, not only to teach us in righteousness as God’s people, but to humble us and bring us to repentant awareness of our sin. So as we see this morning that we are not faithful, that we have not been faithful in the past, and that even as we walk with the Lord, we do so stumblingly, and often sin—what we are supposed to do is stumble back, again and again, to the throne of God’s mercy and grace.
Our words and our works have not lived in harmony. Our words have often promised more than our works have performed. One thing this reality is supposed to do is to lift our eyes off of ourselves and onto the One who is called Faithful and True. It is to lift our eyes to the One who has never promised without performing, whose ‘Yes’ is yes indeed.
Our God is an oath-fulfiller. He is a promise-keeper. He is faithful. Our Lord is sinless and stable and tenaciously faithful. And the glory of glories embedded in that truth is that he has promised us great things.
He has promised us that when we confess our sins, he is faithful and just to forgive us our sin and cleanse us from all unrighteousness.
He has promised us that even though our outer self might waste away, he is the God of resurrection, who renews our inner self day by day.
He has promised that he will never cast us out who truly shelter in him.
So even as we come to the Lord’s Table, even as we sing in worship, and even as we go from this table to our own tables, and from this house to our own houses, we do so looking to, eyes fixed on, this good and faithful God, and his sure and steady promises.