Overcoming Our Deceitful Hearts | Matthew 5:33-37
Jesus leads us through three steps toward overcoming our deceitful hearts: (1) recall the limitation: swearing falsely; (2) grasp the implication: equivocation; and (3) adopt the application: truthfulness. This sermon is part 5 of “Messiah's Righteousness,” Bryan Craddock’s verse-by-verse sermon series on Matthew 5.
How do you feel about where technology is headed? Developments in robotics and artificial intelligence seem like the stuff of science fiction, and that has some people worried. They fear that just like in the movies a glitch in the programming might lead the machines that we have created to perceive human beings as the world’s real problem. Rather than serving us, they will keep saying what we want to hear as they prepare to revolt against us.
I’m skeptical that anything like that could ever happen with machines. Our fears about technology seem more like a projection of our own story. In a sense, the first sin introduced a glitch into our programming. It skewed our perception and distorted our processing, so that we see our Creator as a hindrance and a problem. Rather than serving him, many of us say what we think he wants to hear while we revolt against him.
The Lord confronted this problem in his people through the Prophet Jeremiah. It had been eight hundred years since they received the Law through Moses. The Lord had given them the promised land and made them a great nation, but they kept turning away from him. So, Jeremiah 17:9-10 says,
The heart is deceitful above all things, and desperately sick; who can understand it? "I the LORD search the heart and test the mind, to give every man according to his ways, according to the fruit of his deeds."
If there is any idea about which most people today agree, it’s that you should follow your heart. But these words from Jeremiah reveal the folly of that sentiment.
Our hearts cannot be trusted. We like to tell ourselves that it’s not that bad. We just need a little moral guidance, and some people assume that this is what Jesus was doing in his Sermon on the Mount. But his argument is that we all push against the boundaries of God’s commands and distort their intent. He shows how this happens with the prohibition of murder in Matthew 5:21-26 and with adultery in verses 27-32.
The only way that we can escape God’s condemnation is for someone else to fulfill the Law on our behalf, and that is what Jesus says that he came to do. He satisfied the Law’s demand for atonement through his death for us and met the Law’s requirement of righteousness for us through his obedience. He also sends the Holy Spirit into our lives to begin transforming us so that we can overcome our murderous, adulterous hearts.
As we continue in Matthew 5:33-37, Jesus leads us through three steps toward overcoming our deceitful hearts. He again recalls the limitation, helps us grasp its implication, and calls us to adopt its practical application in everyday life. At first glance, this passage may not seem as relevant to us today as the others in the chapter. But it addresses the fundamental glitch in our thinking that fools us into thinking that we can get away with sin. We will never be able to change or grow unless we overcome that deceitfulness. Jesus begins that process by taking us back to the Law.
Recall the Limitation
Swearing Falsely
Most people consider the United States a very litigious country. We hear about trials and lawsuits all the time in the news. But a 2024 poll showed that only 1 in 3 U.S. adults live in households where someone has been involved in a court case. Statistically, most of us will never take the witness stand to testify under oath. So, why does God bother to say, “You shall not bear false witness against your neighbor” in the Ninth Commandment? Did he expect ancient Israel to be even more litigious than we are? I doubt it.
As I’ve explained previously, we need to think of the Ten Commandments as the outer perimeter of obedience. Instead of pressing up against those boundaries, we must seek his righteousness at the center. Jesus points us in this direction in Matthew 5:33 as he recalls the limitation of swearing falsely. 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.'
Earlier in the sermon, he quotes the Sixth Commandment about murder and the Seventh Commandment about adultery. His words here relate to the Ninth Commandment, but he does not quote it. He steps back from its formal courtroom terminology and gives a summary of other commands from the Law.
Swearing is what we do to assure someone that we are telling the truth, particularly when we make promises to them. Even today, people often appeal to God when they swear some kind of oath. In and of itself, that practice is not bad. In fact, God commanded the people of Israel to do it. Deuteronomy 6:13-14 says,
It is the LORD your God you shall fear. Him you shall serve and by his name you shall swear. You shall not go after other gods, the gods of the peoples who are around you--
The Law presents the Lord as the one true God. He is the master that his people should serve. They should fear him rather than fearing the false gods of other nations. So, one practical expression of that fear was to swear by his name rather than the name of some other god. But swearing by his name was not supposed to be taken lightly. In Leviticus 19:12, the Lord says,
You shall not swear by my name falsely, and so profane the name of your God: I am the LORD.
In this verse, we hear echoes of both the Ninth Commandment about bearing false witness and the Third Commandment about taking the Lord’s name in vain. They intersect because when you swear by God’s name, you are putting his reputation on the line. Keeping your word becomes a commitment to him. So, breaking such an oath is an act of disobedience and disrespect. It shows that his name and reputation do not really matter to you.
So, is God’s concern limited to oaths and formal promises? Certainly not! This limitation of not swearing falsely points to God’s hatred of all falsehood. In fact, David connects the two ideas in Psalm 24:3-4 by saying,
Who shall ascend the hill of the LORD? And who shall stand in his holy place? He who has clean hands and a pure heart, who does not lift up his soul to what is false and does not swear deceitfully.
Falsehood and lies violate God’s holy standard. They disqualify us from drawing near to him. That is a serious problem for us with our deceitful hearts. There are eternal consequences. In Revelation 21:8, God says,
But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death.
We may never spend time in a human court, but we will all stand before the Lord one day. So, we need to be saved from our falsehood, lies, and deceptions. Of course, the good news is that Jesus says in his Sermon on the Mount that he came to fulfill the Law. He atones for our sins and clothes us in his righteousness, and his personal truthfulness is essential to that saving work. The prophecy about his death in Isaiah 53:8-9 says,
By oppression and judgment he was taken away; and as for his generation, who considered that he was cut off out of the land of the living, stricken for the transgression of my people? And they made his grave with the wicked and with a rich man in his death, although he had done no violence, and there was no deceit in his mouth.
Jesus spoke nothing but the truth, and his unrighteous judge, Pontius Pilate, condemned him. But as the ultimate judge of us all, God accepts Jesus’ suffering as the payment to redeem our deceitful hearts. Through faith in him, we can begin to overcome that falsehood, but to do so we must grasp the implication of the prohibition of swearing falsely.
Grasp the Implication
Equivocation
On Valentine's Day everything gets molded into hearts. There are heart-shaped candies, chocolates, cakes and cookies. But I don’t think I have ever seen heart-shaped Jello. It communicates the wrong message to your Valentine. It may be sweet and shiny, but there’s not much substance to it. It jiggles around and gets away from you.
Our deceitful hearts can be just like that. You can say sweet words and make shiny promises, while your heart jiggles around and finds ways to slide around those promises and even around God’s commands. So, after recalling the limitation of falsely swearing, Jesus wants us to grasp its implication for equivocation. To equivocate is to use ambiguous language to avoid commitment or to conceal the truth. That’s what Jesus describes in Matthew 5:34-36. He says,
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.
As we saw earlier, Deuteronomy 6:13 commanded the people of Israel to swear by the name of the Lord their God. But by Jesus’ time, rabbis had identified other oaths that were less binding. He gives the examples of swearing by heaven, earth, Jerusalem, or your own head. The theory was that doing so would leave you a way out of that commitment.
Jesus rejects the distinctions that they were making. Their distorted reasoning tries to limit God and press him into their mold. It assumes that as long as they don’t say his name, they are free and clear to jiggle around and be dishonest. That’s ridiculous!
God has no limitations. He sees through those legalistic games. Heaven, earth, Jerusalem, and even our heads belong to him. As Jesus says in Matthew 10:30, “even the hairs of your head are all numbered.” Nothing is outside of God’s control. So, these lesser oaths are simply equivocations that flow from a deceitful heart.
Now some people interpret Matthew 5:34 to mean that Christians should never take a formal oath in court or in any other setting. But I doubt that this is what Jesus intended. His focus is on the heart not on drawing new boundaries. Plus, Revelation 10:6 tells us that a holy angel swears by him who lives forever and ever. I suppose you could say that angels are exempt from this command. But if all oaths are forbidden for Christians, does that extend to vows and other promises? There is no mention in the New Testament of a Christian taking an oath, but Acts 18:18 says that Paul had taken a vow in Corinth.
It is also important to recognize that the same word that Jesus uses here for taking an oath is used to describe how God himself has made promises. In Luke 1:73-75, Zechariah, the father of John the Baptist, speaks of,
the oath that he swore to our father Abraham, to grant us that we, being delivered from the hand of our enemies, might serve him without fear, in holiness and righteousness before him all our days.
That oath that God made to Abraham is one of the early steps in his saving plan. According to Genesis 12:3, God promised that all the families of the earth would be blessed in Abraham. Jesus came to bring that about. By fulfilling the Law, he makes it possible for us to draw near to God and to have hope. So, as Zechariah says, we can serve God without fear. We can live with confidence, because God himself swore an oath.
In fact, doubting God and his oath is what leads to the equivocation that we are talking about. Sometimes people use deceptive oaths and false promises to exploit others. Think of a dishonest salesman who will say anything to get your money, or a politician who will say anything to get your vote. They don’t believe that God will hold them accountable for their actions. But there are many occasions in the Old Testament when God swears to bring judgment. Hebrews 3:11-12 quotes one of those verses (Psalm 95:11) and applies it to us. It says,
"As I swore in my wrath, 'They shall not enter my rest.'" Take care, brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God.
God’s determination to punish sin stands as a warning to those who would use equivocation to exploit people. But others resort to using equivocation because they are afraid. They make oaths and promises to get themselves out of a scary situation. The Apostle Peter did that. He promised Jesus that he would not fall away. But after the Jewish leaders arrested Jesus, Peter denied knowing him. In fact, Matthew 26:73-74 tells us,
After a little while the bystanders came up and said to Peter, "Certainly you too are one of them, for your accent betrays you." Then he began to invoke a curse on himself and to swear, "I do not know the man." And immediately the rooster crowed.
Does it matter that he didn’t swear by God’s name? No. He denied Christ with a false oath. We can sympathize with his fear. Jesus was being beaten and interrogated at that moment, and would later be scourged and crucified. But Peter could have still responded differently. He should have boldly confessed his faith in Jesus, drawing confidence from God’s sworn promises of salvation and judgment.
You might not ever experience that kind of threatening situation. But do you equivocate about your commitment to following Christ? Have you made promises to God that you aren’t seeking to fulfill? Do you say one thing and deny it by how you live? We must confess that we all have deceitful hearts and that we need Jesus to save us and to help us overcome. So, Jesus gives us an application to adopt.
Adopt the Application
Truthfulness
Chameleons are known for their incredible ability to change the color of their skin. Scientists claim that this helps them to regulate their body temperature and to communicate their intentions to other chameleons. It can also camouflage them so that they blend in with their surroundings. How they achieve that is still somewhat mysterious. But it seems to fit well with another unusual ability that they have. They can move their eyes independently, so that they can look in different directions at the same time.
Our deceitful hearts lead us to be spiritual chameleons. We can’t change our skin or look in different directions at the same time, but we still find ways to blend in with our surroundings. We do it by how we dress, by how we behave, and particularly by how we speak. We say what people want to hear, whether we mean it or not, even when we gather as a church.
So, to overcome our deceitful hearts, it’s not enough to stop short of swearing falsely. We must overcome our equivocation, and to do that Jesus calls us to adopt the application of truthfulness. In Matthew 5:37, he says,
Let what you say be simply 'Yes' or 'No'; anything more than this comes from evil.
The King James Version says, “But let your communication be, Yea, yea; Nay, nay.” As funny as that sounds, it captures the simple directness of Jesus’ words. He speaks that way because he wants all of us who follow him to be simple and direct. We must say what we mean and mean what we say.
When Jesus says that anything more comes from evil, he could be referring to Satan as the evil one. He made that connection on another occasion as he confronted some of his Jewish critics. In John 8:44, he says,
You are of your father the devil, and your will is to do your father's desires. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he lies, he speaks out of his own character, for he is a liar and the father of lies.
That may seem like a great put down to use against your enemies, but it applies to all of us. As fallen sinners, we are all children of the father of lies. He blinds our eyes (2 Cor 4:4) and holds us captive to do his will (2 Tim 2:26), but there is hope. John 8:31-32 tells us,
So Jesus said to the Jews who had believed him, "If you abide in my word, you are truly my disciples, and you will know the truth, and the truth will set you free."
To abide in Jesus’ word is to live in it. We must accept it as the truth and allow it to shape our outlook, so that we can be free from all the lies that Satan uses to control the world. We must then let it guide our steps, so that we grow to walk in it consistently. It must also control what we say and even how we speak. In Ephesians 4:25, Paul says,
Therefore, having put away falsehood, let each one of you speak the truth with his neighbor, for we are members one of another.
Previously, we saw that earlier in that chapter Paul talks about putting off the old self and putting on the new created in the likeness of God. We see that process in this verse. It is not enough to understand truth and put away falsehood. We must go farther. We must learn to speak the truth, not as a show of piety but out of genuine concern for people. This is how we grow spiritually. Back in verse 15, Paul says,
Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ.
So, being truthful does not mean being obnoxious. As we learn in 1 Corinthians 13, love is patient and kind. It is not arrogant or rude. It is not irritable or resentful. It bears all things, believes all things, hopes all things, and endures all things. But love also rejoices with the truth. (1 Cor 13:4-7). Is that how we speak? To overcome our deceitful hearts, we must become people of the truth!
__________
Jesus wants us to recall the limitation of swearing falsely, so that we grasp its implication for our sinful equivocation. We all have deceitful hearts that are controlled by the father of lies. But through Jesus’ death and resurrection, we can be forgiven. Through his life and teaching, we can be set free to adopt the application of simple truthfulness in what we say and do.
Do you believe in God’s truth? Are you living in the word of Christ? If not, I invite you to start today. Begin learning from God’s word. Let the Spirit of God use it to give you life and transform you. If you want to learn more about the powerful change that it brings, I encourage you to read Ephesians 4.
Perhaps you have been a believer for a while but have drifted back into worldly ways of thinking and living. If so, would you commit to walk in truth? Don’t equivocate and play games with it like a spiritual chameleon. Say no to lies and yes to truth, no to sin and yes to God. If you are already doing that, then don’t remain silent. Seek to grow in speaking the truth in love.
May the truth of Christ resound in and through us!
Reflect
Under what circumstances are you tempted to deny the truth?
What steps could you take to walk in truth more consistently?
What could you do to prepare yourself for speaking the truth in love?