In an age when trust is increasingly difficult to find, Christians are called to become people whose words can be trusted. The Ninth Commandment—“You shall not bear false witness against your neighbor”—is about far more than telling the truth in a courtroom. It calls us to become people who speak truthfully, protect the good name of others, and faithfully bear witness to Jesus Christ.

The question is not simply, “Do I lie?” The deeper question is: “Am I becoming a person whose words consistently reflect the truth of God?”

The Ninth Commandment Is About More Than Courtrooms

The commandment against bearing false witness is rooted in the importance of truthful testimony. In ancient Israel, witnesses played a critical role in matters of justice. Deuteronomy 17:6 required the testimony of two or three witnesses before someone could be put to death.

That principle protected people from being condemned on the word of a single false accuser.

But Scripture takes the commandment beyond the courtroom. Bearing false witness can include lying, slander, spreading rumors, concealing the truth, perverting the truth, backbiting, and damaging someone's reputation.

The Westminster Larger Catechism captures the breadth of the commandment by describing many different ways we can violate it—not only through what we say, but through how we use our words to harm others.

In other words, the Ninth Commandment reaches into every place where we use words about other people: our homes, workplaces, schools, neighborhoods, churches, and online conversations.

Your Neighbor Includes the Person on Your Screen

One of the challenges of modern life is that our words can travel farther and faster than ever before.

A single social media post can damage someone's reputation. An accusation can spread before the truth has an opportunity to catch up. Online conversations can quickly become an unforgiving courtroom.

The Ninth Commandment reminds us that our neighbors aren't only the people standing beside us. They are also the people we talk about, post about, comment about, and discuss online.

With our hands, we can take someone's possessions. With our words, we can take something else: their good name.

The commandment therefore calls us not merely to avoid lies but to protect the reputation and dignity of our neighbors.

We Live in a Crisis of Trust

Truthful testimony matters because much of what we know comes through other people.

We know things because teachers teach us, parents tell us, journalists report to us, and people with knowledge share what they have learned. We depend on witnesses.

But what happens when we no longer know which witnesses to trust?

The sermon describes the present moment as an age of uncertainty about whom we can believe. We can be skeptical of experts while simultaneously being remarkably willing to believe things we encounter online.

That creates a significant challenge for Christians because the church has something important to say to the world: the gospel of Jesus Christ.

We are witnesses to good news. We proclaim that Jesus came into the world to save sinners and that He is risen. But if the people delivering that message are not trustworthy, our witness is weakened.

Jesus Is the Truth We Are Called to Witness

The theme of witness runs throughout the Gospel of John.

Jesus' miracles testified to who He was. The man born blind testified that Jesus had healed him. Even Jesus' enemies provided testimony—although their accusations were false and distorted.

Most importantly, God the Father testified about Jesus. At Jesus' baptism and transfiguration, the Father declared that Jesus is His beloved Son.

The Gospel of John ultimately presents the reader with a question: Who is Jesus?

After hearing all the testimony, each person must decide how they will respond to Him.

Jesus Himself said that He came into the world to bear witness to the truth.

And the truth is not merely an idea. Jesus is the truth.

God cannot lie. His Word can be trusted. And Jesus is God's Word made flesh. Revelation describes Him as the “faithful and true witness.”

As followers of Jesus, we bear His name and His image. Therefore, we should aspire to become people who tell the truth because we belong to the One who is truth itself.

Jesus Wants Truth to Become Our Default

Jesus takes the idea of truthful speech even further.

In Matthew 5, Jesus teaches that His followers shouldn't need elaborate oaths to prove that they're telling the truth. Instead, He says, “Let your yes be yes and your no, no.”

The goal isn't to avoid lying when we're under oath. The goal is to become trustworthy people.

Our everyday words should be characterized by truthfulness so consistently that people don't need us to swear that we're telling the truth.

Jesus even warns that we will give an account for our careless words.

This means the Ninth Commandment isn't just about avoiding a particular behavior. It is about forming a particular kind of person—a person full of truth rather than empty words.

Peter Shows Us What Fear Can Do

The story of Peter gives us a powerful picture of both failure and restoration.

When Jesus was arrested, Peter was afraid. Three times, he denied knowing Jesus.

Peter had the freedom to speak, but he used that freedom to deny both Jesus and his own identity as a disciple.

Many of us can relate.

There are moments when fear, embarrassment, social pressure, or the desire to protect ourselves can make silence seem easier than speaking the truth about Christ.

Peter's story, however, doesn't end with his failure.

Jesus Restores the Witness Who Failed

After His resurrection, Jesus meets Peter again.

Jesus doesn't remind Peter of his failure. Instead, He asks him three times, “Do you love me?”

Then Jesus gives Peter a mission: “Feed my sheep.”

The man who once denied knowing Jesus is restored and recommissioned to tell the world who Jesus is.

That is an important reminder for Christians who recognize their own failures. Jesus doesn't merely forgive Peter; He gives him a renewed purpose.

Love for Jesus frees us from the fear that keeps us from bearing witness to Him.

Become a Truth-Telling Witness

The world needs trustworthy witnesses.

That doesn't mean Christians will always be popular. Speaking the truth can sometimes come with a social cost. But the calling remains.

We are called to tell the truth about our neighbors.

We are called to tell the truth in our homes and workplaces.

We are called to tell the truth in our churches and communities.

And, most importantly, we are called to bear true witness to Jesus.

The Ninth Commandment isn't ultimately about becoming people who are afraid of saying the wrong thing. It is about becoming people whose words and lives reflect the truth of God.

In an age of distrust, the people of God should stand out—not because we are louder, angrier, or more certain of ourselves, but because we are trustworthy witnesses who tell the truth as an expression of love for our neighbors.

Let Truth-Telling Become a Way of Life

“Do you swear to tell the truth, the whole truth, and nothing but the truth?”

The sermon ends with a twist: for Christians, the answer shouldn't require an oath.

Truth-telling should already be our default.

We don't need to swear that we'll tell the truth if we are becoming people whose lives are marked by truthfulness.

So the challenge is this:

Love Jesus. Love the truth. Speak the truth. And let your words and your life bear faithful witness to Christ.

The world needs truth-telling witnesses—and becoming one is a powerful way to love our neighbors.