The Truth
If I want to get away with something—where I’m not really lying to you, but I’m not really telling you the truth—what should I do? Cross my fingers. That’s all I’ve got to do, and I can say anything! That’s essentially what Jesus is dealing with in today’s text. The religious leaders had boiled oaths down to a religious crossing of the fingers, and Jesus shows us we must be more than people who don’t lie. We must be people of truth. This didn’t just matter for Jesus then. It matters for us today. In a world inundated with fake news, we must be a people who are counterculturally dedicated to the truth.
God gave oaths to uphold truth. (33)
Jesus says in 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.’” That’s not one verse pulled out of the Old Testament but really a summary of several passages. It alludes to:
Exodus 20:7 - You shall not take the name of the Lord your God in vain, for the Lord will not hold him guiltless who takes his name in vain.
Leviticus 19:12 - You shall not swear by my name falsely, and so profane the name of your God: I am the Lord.
Numbers 30:2 - 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.
Deuteronomy 23:21-23- 21 ”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. 22 But if you refrain from vowing, you will not be guilty of sin. 23 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.
Put together, the message is simple: you must keep your word, especially when you vow something before the Lord.
The Old Testament didn’t forbid oaths. It was actually commanded. Deuteronomy 6:13 says, “It is the Lord your God you shall fear. Him you shall serve and by his name you shall swear.” R. Kent Hughes says, “Vows were assumed, even encouraged. But once made, they were not to be broken under any circumstances. The Bible taught that they were very serious business.”[1] What was forbidden was to swear and not to do it. To swear falsely was to profane God’s name.
God Himself swore. And Scripture is full of examples. After the flood He swore to Noah that He would never again destroy the world in that way (Genesis 9:11).
“I establish my covenant with you, that never again shall all flesh be cut off by the waters of the flood, and never again shall there be a flood to destroy the earth.”
He swore to Abraham that He would bless his offspring (Genesis 22:16–17).
16 and said, ”By myself I have sworn, declares the Lord, because you have done this and have not withheld your son, your only son, 17 I will surely bless you, and I will surely multiply your offspring as the stars of heaven and as the sand that is on the seashore. And your offspring shall possess the gate of his enemies,
God swore to David that one of his descendants would sit on the throne forever (Psalm 132:11).
The Lord swore to David a sure oath
from which he will not turn back:
“One of the sons of your body
I will set on your throne.
Hebrews 6:17 tells us why: “So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath.”
Paul also calls God as his witness multiple times.
Romans 1:9 - “For God is my witness, whom I serve with my spirit in the gospel of his Son, that without ceasing I mention you.”
2 Corinthians 1:23 - “But I call God to witness against me—it was to spare you that I refrained from coming again to Corinth.”
Paul understood that when he invoked God’s name, he was placing his words under God’s scrutiny. Every vow, every promise, every declaration we make is made before God. Every oath is a testimony to truth.
The Pharisees turned oaths into loopholes for lying. (34-36)
Here’s where things had gone wrong by Jesus’s day. Oaths were supposed to uphold truth. But the religious leaders had turned them into a way of justifying lies. I want you to notice the first part of the things Jesus says here in verses 34–36, “34 But I say to you, Do not take an oath at all, either by heaven, for it is the throne of God, 35 or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. 36 And do not take an oath by your head, for you cannot make one hair white or black.”
We learned about the Mishnah last week. It was a collection or rabbinic teachings. During Jesus’s time, rabbis weren’t just teaching from the Torah, but they were teaching from the traditions and teachings of other rabbis. That’s why Jesus keeps saying, “But I say to you.” He is exerting His ultimate authority over all of these other teachers.
The Mishnah has an entire lengthy section on oaths. In it, rabbis debated which oaths counted and which ones didn’t. Throughout different rabbinic teachings, there were so many different clauses on what counted as a binding vow or not. I read many of them straight from the sources this week. Here are just a few I found:
If you swore by Jerusalem, you weren’t bound. But if you swore toward or as Jerusalem, then you were bound to your word.[2] Another is if you swore by the Torah, you weren’t bound, but if you swore by the contents of the Torah, you were.[3] That’s like “I promise on the Bible,” verse “I promise on the very words of God.” Another one is that if you swear by heaven or earth you are not bound, but if you swear by any iteration of God’s name, you are bound.[4] That’s the difference of “Heaven is my witness,” or “God is my witness.”
Hughes describes it as “a profound spiritual schizophrenia: ‘I’m not telling the truth, but I’m really not lying.’”[5] It was the religious version of crossing your fingers behind your back. Here’s where the issue lies. They found oaths binding when it was centered on God. Toward Jerusalem is where God was. In the words of the Torah is where God was to be found. The name of Yahweh or Adonai or even in the name of the Gracious and Compassionate One or in the name of He Who is Slow to Anger or in the name of He Who is Abounding in Loving-kindness.
That’s why Jesus says the second part of each statement in verses 34–36, “34 But I say to you, Do not take an oath at all, either by heaven, for it is the throne of God, 35 or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. 36 And do not take an oath by your head, for you cannot make one hair white or black.”
Every word we speak is before God. (34-36)
In other words, Jesus is saying all these clever little categories were nonsense. Heaven is God’s throne. Earth is His footstool. Jerusalem is His city. Even your own head belongs to God. The Pharisees thought they could avoid accountability by playing word games. Jesus says no—God hears every word. And twisting God’s Word into loopholes doesn’t make you clever. It makes you a liar.
What Jesus is doing is pressing the point home for us that every word we speak is spoken before God. Every word we say is spoken in the presence of God.
That’s why Jesus points to heaven, earth, Jerusalem, even your own head. They all belong to God. Nothing is outside God’s authority. Nothing escapes God’s attention. Psalm 139:4 says, “Even before a word is on my tongue, behold, O Lord, you know it altogether.”
I love how simply Sinclair Ferguson put it: “No promise can ever be made, no word ever spoken, without it being done in the presence of God.”[6] That means your speech in the courtroom, in your living room, and in the break room all matter the same. God is there. He hears. He knows. And for each word, we will have to give an account. Later on in His ministry, Jesus addresses the Pharisees again, and He says to them in Matthew 12:34-37,
34 You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks. 35 The good person out of his good treasure brings forth good, and the evil person out of his evil treasure brings forth evil. 36 I tell you, on the day of judgment people will give account for every careless word they speak, 37 for by your words you will be justified, and by your words you will be condemned.”
Our need for oaths exposes our tendency toward sin. (37)
Then Jesus concludes in verse 37: “Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil.”
Why do we even need oaths? Because we are sinners. We have deceitful hearts. Bonhoeffer put it like this: “The very existence of oaths is a proof that there are such things as lies. If lying were unknown, there would be no need for oaths.”[7] Hughes says it even more bluntly: “The need for oath-taking and swearing comes from the fact that we earthlings are liars.”[8] The great preacher and writer George Macdonald wrote to his son on December 6, 1878, “I always try - I think I do - to be truthful. All the same I tell a great many lies.”
James, the half-brother of Jesus, repeats Jesus almost word for word: “But above all, my brothers, do not swear, either by heaven or by earth or by any other oath, but let your “yes” be yes and your “no” be no, so that you may not fall under condemnation.” (James 5:12).
The point is not that all formal oaths are evil, but that as followers of Christ, our words should be so trustworthy that we don’t need to add anything. Anything more, Jesus says, comes from evil — or from the evil one. Satan is the father of lies (John 8:44). When our words are full of deception, half-truths, or manipulation, we are echoing the serpent, not the Savior. Jesus calls us to step out of that entire system of darkness and live with simple honesty. Let your yes mean yes. Let your no mean no. No crossed fingers. No blood oaths. No need for even shaking on it or pinky promises. As Christians, our truthfulness is of utmost importance.
God is perfectly true and His people are called to reflect His truth.
All of this is anchored in the character of God. He is true. Numbers 23:19 declares, “God is not man, that he should lie, or a son of man, that he should change his mind. Has he said, and will he not do it? Or has he spoken, and will he not fulfill it?” Titus 1:2 says God is one “who never lies.” Hebrews 6:18 says, “it is impossible for God to lie.”
And as God’s children, we are called to reflect His truth. Ephesians 4:25 says, “Therefore, having put away falsehood, let each one of you speak the truth with his neighbor, for we are members one of another.” Colossians 3:9: “Do not lie to one another, seeing that you have put off the old self with its practices.”
Hughes says it well: “The radically righteous do not need oaths. Their word is truth!”[9] That should be the mark of the Christian! When we speak, people know it’s honest. But we don’t become truthful by trying harder. Like all of these teachings from Jesus we have seen, it must come from a changed heart. Bonhoeffer reminds us,
“Complete truthfulness is only possible where sin has been uncovered, and forgiven by Jesus. Only those who are in a state of truthfulness through the confession of their sin to Jesus are not ashamed to tell the truth wherever it must be told…. Sinful men do not like this sort of truthfulness, and they resist it with all their might. That is why they persecute it and crucify it. It is only because we follow Jesus that we can be genuinely truthful, for then he reveals to us our sin upon the cross. The cross is God's truth about us, and therefore it is the only power which can make us truthful. When we know the cross we are no longer afraid of the truth. We need no more oaths to confirm the truth of our utterances, for we live in the perfect truth of God.”[10]
We must see the truth about ourselves before we behold the truth of the gospel.
I John 1:8 says, “If we say we have no sin, we deceive ourselves, and the truth is not in us.”
At the cross, our lies are exposed, but they’re also forgiven. Jesus took them on Himself.
Romans 5:8 says, “God shows his love for us in that while we were still sinners, Christ died for us.”
And now we don’t have to live in fear, covering ourselves with deception. We can tell the truth, even when it costs us, because Christ has covered our sin. We know how sinful we are. God knows how sinful were are. And in Christ, we are gloriously and magnificently forgiven and cleansed!
We need to see the reality of our depravity before we can ever see the glories of the gospel. This is true for Christians and non-Christians alike. This is true for those who need to come to faith in Christ, and this is true for those who need the joy of the Lord and to enjoy fellowship with other believers.
Hear me: You are not as good as you think you are. Hear me: You are not as right as you think you are. You need to let those truths settle upon you for humility to take root. Hear me: You are far more beloved than you could ever think you are. And that’s the truth.
[1] R. Kent Hughes, The Sermon on the Mount (Crossway, 2001), 125.
[5] Hughes, The Sermon on the Mount, 126.
[6] Ferguson, The Sermon on the Mount, 97.
[7] Bonhoeffer, The Cost of Discipleship, 152.
[8] Hughes, The Sermon on the Mount, 127.
[9] Hughes, The Sermon on the Mount, 127.
[10] Bonhoeffer, The Cost of Discipleship, 155.
