Suppose you go to the doctor because something just does not feel right.
They run the scans. The doctor walks into the room, sits down, and says, “We found something. It is aggressive. It is dangerous. And we need to cut it out.”
Those are harsh words.
But at that moment, you do not want a doctor who is so afraid of upsetting you that he ignores what is killing you. Sometimes love speaks softly. Sometimes love puts an arm around you. And sometimes love looks you straight in the eye and says, “This is killing you. It has to be removed.”
That is what Jesus does in Mark 9:38–50.
These are some of the harshest words Jesus ever spoke: a millstone around your neck, cutting off a hand or foot, tearing out an eye, hell, unquenchable fire.
Why would a loving Savior speak like that?
Because He loves His people too much to let us destroy one another, and He loves us too much to let us play with the sin that is destroying us.
Your Group Is Not the Kingdom
Just before this passage, the disciples had been arguing over which one of them was the greatest. Jesus responded by teaching them that greatness in His kingdom looks nothing like greatness in the world. The first must become last. The greatest must become servant of all.
But pride does not die easily.
Before the lesson is even over, John tells Jesus, “We saw someone casting out demons in Your name, and we tried to prevent him because he was not following us.”
Do not miss the irony. Just a few verses earlier, the disciples themselves had failed to cast a demon out of a boy. Now an unnamed outsider is successfully doing it in Jesus’ name.
You can almost hear the jealousy: “Jesus, we tried to stop that guy. He is not one of us.”
Last week pride asked, “Which one of us is greatest?”
Now pride asks, “Who gets to be one of us?”
Same pride. Different clothes.
Jesus responds, “Do not hinder him.”
He is not saying doctrine does not matter. Of course doctrine matters. There are truths about Scripture, Christ, the gospel, and the nature of God that are worth defending.
But Jesus is confronting something different. He is not erasing theological boundaries. He is attacking tribal boundaries.
We can confuse loyalty to our circle with loyalty to Christ. Baptist. Reformed. Traditional. Premillennial. Amillennial. Cessationist. We can look suspiciously at another church doing faithful gospel work simply because they are not quite like us.
Convictions matter enormously.
But your group is not the kingdom.
Christ has servants you did not train, churches you did not start, and ministries you do not control. One of the sharpest tests of pride is whether you can celebrate what Jesus is doing through somebody else—especially when they are succeeding where you are struggling.
If Christ is being honored, can you rejoice?
Pride has an incredibly difficult time applauding others.
Handle Those Who Belong to Christ With Care
Jesus then turns from the outsider to the way His disciples treat those who belong to Him.
“Whoever causes one of these little ones who believe to stumble,” He says, faces terrifying consequences.
These “little ones” include ordinary, vulnerable, immature believers—people whose faith may be easily wounded.
Jesus is saying: Be careful how you treat them.
An older Christian can deeply wound a younger Christian. A pastor can wound a church member. A teacher can wound someone in a class. A parent can wound a child.
Hypocrisy can do it. Theological arrogance can do it. Gossip and moral compromise can do it. So can constantly making someone feel as though they will never quite be one of us.
Sometimes the church can become the place where we shoot our wounded.
Jesus says, in effect, “Not among My people.”
Why does He use such severe language?
Because the believer you think is least is exceedingly precious to Him.
They may be immature. They may say the wrong thing. They may not understand what you have spent thirty years learning.
What they need is patience and discipleship.
Handle them with care. They belong to Jesus.
And then Jesus turns the knife toward our own hearts.
Verse 42 says, “Do not cause somebody else to stumble.”
Verse 43 says, in effect, “Now let’s talk about what causes you to stumble.”
Be Ruthless With Your Own Sin
Pride often reverses Jesus’ commands.
We are ruthless with everybody else’s sin and incredibly patient with our own.
Jesus says the opposite: Be tender with the struggling believer and violent toward the sin in your own heart.
“If your hand causes you to stumble, cut it off.”
“If your foot causes you to stumble, cut it off.”
“If your eye causes you to stumble, throw it out.”
Jesus is using shocking hyperbole. He is not commanding physical mutilation. A blind man can still lust. A man without hands can still be greedy. A man without feet can still be proud.
You cannot perform physical surgery on a heart problem.
Jesus is calling for mortification—the putting to death of sin.
Some sins become so attached to us that they feel like part of us: a relationship, a habit, an appetite, an ambition, a way of coping. We have lived with them so long that we cannot imagine life without them.
Jesus says: If it is destroying you, it has to go.
What might that mean practically?
Delete the account. Get rid of the app. Cancel the subscription. Give somebody else the password.
Stop going to the place where you repeatedly fall.
End the behavior. Stop sending the messages. Leave the relationship. Throw away what keeps feeding the addiction.
Take whatever external action is necessary to stop feeding the internal sin.
We are not saved because we successfully cut enough sins out of our lives. Salvation is entirely by grace through faith in Jesus Christ. Jesus lived the righteous life we could not live, died under the judgment our sin deserved, and rose from the grave.
But saving grace does not merely forgive the guilt of sin and then leave us content beneath its rule.
Grace teaches us to fight.
Which Loss Is Better?
Jesus repeatedly uses one word: better.
Better to enter life maimed than keep what is destroying you. Better to lose something now than lose everything forever.
We often ask, “Will giving this up hurt?”
Of course it will.
But Jesus is asking a different question: Which loss is better?
Sin always promises more than it can deliver. At first, you consume it. Eventually, it starts consuming you.
Sin destroys trust. It destroys intimacy. It torments the conscience. It divides homes. It cripples usefulness. And we can spend decades fighting something we should have cut off years ago.
For the person outside Christ, Jesus’ warning about judgment is real. You cannot amputate enough sin to make yourself acceptable to God. You need a Savior. You need forgiveness and a new heart. You need Jesus.
And Christian, while there is no condemnation for those who are in Christ, do not imagine that playing games with sin is harmless.
Stop petting what Jesus told you to kill.
Following Jesus means our whole lives belong on the altar—our hands, feet, eyes, ambitions, desires, relationships. All of us belongs to Him.
Sometimes obedience burns. Sometimes killing sin hurts. Sometimes following Jesus means surrendering something we desperately want to keep.
But Jesus ends where He began: “Have salt in yourselves, and be at peace with one another.”
John wanted to cut another believer off.
Jesus says: Wrong target.
Do not be ruthless with your brother and gentle with your sin.
Be gentle with your brother and ruthless with your sin.
Where has pride made someone else your competitor instead of your brother or sister? Is there one of Christ’s “little ones” you need to treat with greater care? And what do you already know Jesus is telling you to cut out of your life?
Do not negotiate with it. Do not manage it. Do not excuse it.
By the power of the Spirit, kill it.
Because every believer belongs to Christ and every sin threatens our walk with Christ, humbly welcome His people and ruthlessly wage war against your sin.
