Nothing but the Truth

Nothing But the Truth
Matthew 5:33–37

When Pilate stood before Jesus, he asked a question that has echoed through the ages: “What is truth?” It’s a question every human wrestles with because truth is at the very core of life. Nothing is more important than truth. Why? Because truth defines what is real. It defines reality itself. That’s why Jesus said, “You will know the truth, and the truth will set you free.” Notice He didn’t say love will set you free, or hope will set you free—only truth has the power to liberate. Truth is fundamental to the essence of life.

Think about it. Imagine sitting in a doctor’s office, and the doctor has just discovered that you have cancer. What do you need in that moment? Do you need love? Not first—because you wouldn’t even understand why the doctor is showing you compassion. Do you need hope? Not yet—because without knowing the truth of your condition, you don’t know what to hope for. Do you need faith? Faith without truth is undefined. What you need most is truth. Only once the truth is revealed can love, hope, and faith have meaning. All our faith in, hope in, and love of God is built on the foundation of truth!

That’s why this passage is so crucial. At first glance, it seems that Jesus is only concerned with oath-taking. But when we look more closely, we see that His real concern is truth-telling. Oaths exist for one reason: because our words are not naturally trustworthy.

So the aim of Jesus in this passage is simple and searching: Kingdom citizens are truth-tellers. In other words, Christ’s disciples are to be people who tell the truth no matter the circumstance. To unfold this, I want us to consider three movements in the text: the truth, the whole truth, and nothing but the truth.

 

The Truth…for the Ancestors (v. 33)

• In this passage, Jesus introduces the second triad of antithesis statements. He is clarifying what the Law truly intended. In the first triad, He addressed the value of the neighbor: do not hate, do not be unfaithful, do not trivialize others. Now He turns to the rules of engagement once the value of life, faithfulness, and covenant commitment have already been established.
• To make His point, Jesus exposes the state of truth in their society. He says: “You have heard it said, ‘You must not break your oath, but you must keep your oaths to the Lord.’”
• This statement is not a direct quotation from the Old Testament but, as scholars note, a rabbinic paraphrase of passages like Leviticus 19:12, Numbers 30:2, and Deuteronomy 23:21–23. The problem is that this paraphrase created loopholes. It demanded honesty in a courtroom oath or when a vow was made directly to the Lord, but it implicitly excused dishonesty in other settings—so long as it wasn’t perjury or a vow “to God Himself.”
• At the heart of every true oath was the Lord. An Israelite who swore an oath was binding themselves before God. But by swearing “by heaven,” or “by earth,” or “by Jerusalem,” or “by one’s head,” people thought they could sidestep this binding nature.
• As one commentator notes, “In rabbinic law, none of the oath formulas mentioned in verses 34–36 were legally binding since they did not use approved substitutions for the divine name. Such oath formulas gave the impression of sincerity, but in reality, they masked deception.” These technicalities created a socially acceptable way to lie.
• In other words, truth for the ancestors had become a convenient truth—a malleable, bendable truth. Oaths were tools to manipulate. Someone could say, “I promise you by heaven I’ll take buy your house for 350k,” and yet, since it wasn’t “by the Lord,” it wasn’t legally binding.
• Oaths as they were employed back then are not as prevalent now, but something similar is at play in our day and age. We still make promises and commitments, but truth-bending is alive and well. We may not swear by heaven, earth, Jerusalem, or our heads, but we deceive in subtler ways. We cloak dishonesty with vague intentions:
  • “Let me think about it,” or
  • “I’ll pray about it.”
  • These phrases sound spiritual and respectful, and they are if in fact we are going to think about it or pray about it, but often they are evasions—ways to avoid giving a clear yes or no because we fear the cost of commitment.
• As Christians, we can become experts at masking our true intentions. We hide behind what’s often called “Christianese”—language that sounds holy but lacks real devotion.
• Jesus will have none of this. As citizens of His Kingdom, He cares about even our casual conversations and insists that we be known as people who tell the whole truth. But what does “the whole truth” mean for Jesus?

The Whole Truth…for Jesus (vv. 34-36)

• Notice what Jesus says in vv. 34–36. He warns that the objects people swore by—heaven, earth, Jerusalem, or even their own head—were all so closely tied to God that such vows were actually irreverent. To swear “by heaven” was essentially saying, “May heaven be destroyed if I don’t keep my word.” But heaven is God’s throne. To swear “by earth” was to invoke God’s footstool. To swear “by Jerusalem” was to invoke the city of the Great King, which is God himself. Even swearing “by your own head” was blasphemous, because it implied, “May I be decapitated if I fail.” Yet no one can control their own aging—young people cannot stop their hair from turning gray, and the elderly cannot make their hair turn black again. If we cannot control something as simple as the color of our hair, how much less can we control the timing of our death? To swear this way is to claim authority that belongs to God alone.
• For Jesus, the whole truth means abandoning empty formulas. Stop hiding behind promises “by heaven,” “by earth,” “by Jerusalem,” or “by your head.” Or, “Let me think about it,” or “I’ll pray about it.” If you know that you are not even going to think or pray about it since you have already made up your mind. Instead, simply speak the truth.
• We often miss the broader implications. Just as last week we saw that God’s teaching on divorce is not simply “stay married” but “pursue a thriving marriage,” so here, oath-taking is not the fundamental point. Fundamentally, Jesus is concerned with truthfulness.
• The truth for Jesus is oathless. Oaths exist only because our words are untrustworthy. To require an oath presupposes that our normal speech cannot be trusted. But citizens of the Kingdom are to be different—our word must be reliable, our speech full of truth, our lives a consistent witness to reality as God defines it.
• In essence, Jesus is saying: Stop lying and pretending your words carry truth just because you attach an oath to them. Instead, let your life itself demonstrate truthfulness. And that’s why He concludes in verse 37…

Nothing but the Truth (v. 37)

• Jesus’s disciples are called to be consistently and completely honest. They should never affirm what is false or deny what is true. When this kind of honesty marks our lives, there is no need for oath formulas.
• The defining mark of a Kingdom citizen is truth-telling. Some may object and say, “Wait—I thought love was the fundamental characteristic of the Kingdom. Didn’t Jesus say, ‘By this all people will know you are my disciples, if you love one another’?” That’s true, but love cannot be separated from truth. Love must be defined by truth; otherwise, it becomes empty sentiment. That’s why Paul exhorts us to speak the truth in love, not simply to speak love in vague terms. Jesus Himself said, I am the way, the truth, and the life—meaning that the way to life is always through truth. At His very core, God is a truth-teller. He reveals reality as it is. In Him there is no deception, no shadow, no falsehood. If God did not speak truth, reveal truth, and show truth, we would be the most pitiable of all people.
• Jesus concludes by warning that anything beyond simple honesty comes from the evil one. Satan is the “father of lies” (John 8:44). The practice of deception, even if dressed up with oaths, belongs to his influence.
• This takes us back to the Garden of Eden. The serpent deceived Eve with half-truths, twisting God’s word to produce doubt and rebellion. When we rely on half-truths or manipulate words to mislead, we are imitating the serpent himself. To tell less than the truth is to join in the devil’s work.

Main Point: Kingdom citizens are truth-tellers

 

Why? Because God gives us Nothing but the Truth

In the book of Numbers, we read that “God is not a man, that He should lie, nor a son of man, that He should change His mind” (Num. 23:19). God always gives us nothing but the truth—nothing but what is real. The apostle Paul echoes this in 2 Corinthians when he declares that all of God’s promises find their Yes and Amen in Christ (2 Cor. 1:20).

Oaths, God, and Us

Jesus is not forbidding oaths in absolute because then you wouldn’t be able to sign a contract, say to rent or buy a house. All of God’s covenants are oaths, we could say promises. He is forbidding oaths in your day-to-day relationships and he is saying that our words should be trustworthy enough that we shouldn’t need legal promises indicating that we will abide by what we said. Let your word be yes or no, and that is it. The truth, the whole truth, and nothing but the truth!

 

Application – Live the Truth

How then do we live the truth? Hear Paul’s words in Ephesians 4:25: “Therefore, having put away falsehood, let each one of you speak the truth with his neighbor, for we are members one of another.” For a community to thrive in trust and confidence, truth is essential.

Paul shows us what this looks like:

1. Speak the Truth

Why do oaths exist? Because we are untrustworthy. We have to promise because doubt is our natural response in a world filled with broken words. To live as truth-tellers, we must guard against three dangers:

• Careless words.
  Too often we make empty promises—not always maliciously, but carelessly. We promise more than we can deliver, sometimes to look good or gain praise. Even the promises you make to yourself matter: if you don’t keep them, you’ve lied to yourself. Let’s not pretend to know more than we know or commit to more than we can do.
• Cowardice.
  Our goal is not to be “nice,” but to be faithful. Yet we often shrink back from truth because we want to be liked. We dance around it like we’re at a wedding reception, afraid to offend. But Jesus never dealt in flattery—he spoke the truth plainly. Sometimes truth-telling will cost.
• Redefining truth.
  Don’t twist words to justify broken promises. If you said, “We’ll meet at 9,” but later insist you meant “9 past 10,” that is not clever—it’s dishonest. Avoid secrecy, distortions, exaggerations, or theatrics that mislead.

2. Live Not by Lies

We also live in an age that denies truth altogether. The mantra of our generation is: “There is no absolute truth.” But that is a self-refuting claim—because if it’s true, then truth exists!

Paul describes truth as a belt in the armor of God (Ephesians 6). A soldier’s armor is useless without the belt holding it together. So it is with us: truth girds us up for spiritual battle.

Aleksandr Solzhenitsyn, on the day of his arrest in 1974, left his people one final exhortation: “Live not by lies.” He knew he could not overthrow the Soviet regime, but he could refuse to be its loyal subject. He urged ordinary people:

• Do not say, write, or distribute anything that distorts truth.
• Do not attend rallies or meetings where lies are forced.
• Do not vote for candidates or proposals you know to be false.
• Walk out when propaganda is spoken.
• Do not support journalism that hides facts.

Solzhenitsyn’s call remains ours: if we cannot shout truth from the rooftops, we can at least refuse to affirm what we know is false.

3. Know the Truth

Finally, we cannot live the truth unless we know the truth. That’s why doctrine matters. Article 2 of the Belgic Confession reminds us that God makes himself known in two ways:

• Through creation. The universe is like a beautiful book, with every creature a letter pointing to God’s eternal power and divine nature (Rom. 1:20).
• Through Scripture. God reveals himself more clearly by his holy Word, giving us all we need for his glory and for our salvation.

 

Whatever you think about Charlie Kirk, the reality is that he was killed because he spoke truths his attacker despised. Truth can be costly, but it is never optional. We can never live by lies, which means we must be willing to die for the truth!

 

Truth is not only a moral duty but a gift from God. To live it, we must know it—and knowing it, we must speak it.

 

4. Believe the Truth

Why must the citizens of the kingdom speak truth? Because God speaks truth. There are no lies in Him. Jesus said, “I am the way the truth, and the life, and no one comes to the Father except through me.”

 

This passage implicitly invites us to trust our God who is perfectly trustworthy. His promises are never empty platitudes; His warnings are never careless threats. What He says is always reality—both His word of promise (salvation) and His word of warning (judgment against sin).

That leaves us in an awkward position: God is absolute truth, and we are constant liars. Jesus’ command feels impossible. And it is—apart from the gospel.

 

 

The Need for the Gospel

This contrast exposes our desperate need for Christ. God is trustworthy; in Him there is no deception. But we are corrupted by our sin and hounded by the father of lies, Satan himself. This alone shows us our need for forgiveness in Christ.

Here is the good news: God does not lie. He speaks hope and forgiveness in His Son. What then must we do? We must believe the words of the gospel: repent of our lying ways and trust that Christ offers full pardon.

• To those who believe, His word brings life.
• To those who reject it, His word brings judgment.

And here is the wonder of grace: Christ’s forgiveness not only covers our past but gives us new life in the Spirit. By His Spirit, we are empowered to put away falsehood and live not by lies.

So let us cling to this promise today—believing the truth, resting in the gospel, and living as people made new by the God who never lies.

 

Main Point: Kingdom citizens are truth-tellers

 

Conclusion

We are being challenged to speak the truth—no matter the circumstance. Let’s do it! Not in our own strength, not in self-reliance, but in the confidence that we have been born from above and empowered by the Spirit to speak truth, even when it is hard, even when it is costly.

Let’s do it for the sake of our families, for the flourishing of our Christian community, and for the good of our society. Let us be countercultural in our truth-telling—imitating our Father and our elder Brother, Jesus Christ, through the power of the Spirit. Our triune God is ever faithful, ever speaking truth, and never lies.

So let us remember the main point: Kingdom citizens are truth-tellers.