Mark 10: What Is the One Thing You Lack?

Introduction

"And you, what is your one thing?" That is the question Pastor Ruth asks in this message, preached on October 11, 2026 at Fukuoka Agape Church in Japan. The text is Mark 10:17-31, the encounter between Jesus and a rich man who wanted to know how to enter the kingdom of God.

Jesus answers him: "One thing you lack." Just one. And this man, sincere and faithful to the commandments as he was, walks away sad. The pastor adds right away: some of you may say, "Just one? No, I have two, three, four, a mountain of them!"

Through this passage, she invites you to look for what you are still holding in your hand, what you lean on in place of God, and to entrust it to him today.

Outline of the Message

1. Receiving the Kingdom Like a Child

Just before this passage, children run to Jesus and the disciples want to push them away. Jesus says, "Allow the little children to come to me!" and adds that whoever does not receive the kingdom of God like a little child will not enter it (Mark 10:13-16).
A child does not look for a thousand arguments. A child hears that there is a wonderful place and says, "I want to go in, let me in!"
This simple heart is not reserved for children. Adults can also believe in this way, and the kingdom is open to them.

2. A Sincere Man Before Jesus

A man runs up, kneels down and asks, "Good Teacher, what shall I do that I may inherit eternal life?" He had probably heard a great deal about Jesus and respected him as a true teacher, perhaps as the Messiah.
He wanted to make sure his faith was right and that he was walking uprightly. Jesus reminds him of the commandments: do not murder, do not commit adultery, do not steal, do not give false testimony, do not defraud, honor your father and mother.
These are the ten commandments received by Moses, the ones the church had just read in Deuteronomy two weeks earlier (Deuteronomy 5). Mark does not say how old he was, but another Gospel speaks of a "young man" (Matthew 19:20).
The pastor shares a word received in prayer by Park Ji-ye, a missionary in Los Angeles: if you summarized the whole Bible on a single sheet of paper, you would have the ten commandments and the Lord's Prayer taught by Jesus. And if you summarized it further into a single word: "Jesus Christ."

3. Commandments That Still Stand, and Go Deeper

Some Christians, she says, claim that the ten commandments are an Old Testament matter, a goal to aim at and nothing more. "That is unthinkable." The God of the Old Testament, the God of the New Testament and the God we serve today are the same God.
We do not have the strength to keep them perfectly. But Jesus sent us the Holy Spirit, and when we follow him, we become able to keep them. When we fall, we repent with all our heart and walk on again.
With Jesus, the commandments have even become more demanding. Calling your brother a fool, hating, refusing to forgive is already killing in your heart (Matthew 5:21-22). Looking with lust is already committing adultery in your heart (Matthew 5:27-28), and that also applies to women who become excessively attached to pop idols or bar hosts.
Stealing begins with envy: "I want what he has." The pastor stresses that the exclamation "I envy you!" is not a good word for a Christian. Each person has received their own graces: saying "That's beautiful! That's good!" is right. If we let our guard down, sin swells very quickly, like yeast.
Honoring your parents carries a promise of long life (Exodus 20:12). She tells the story of a woman who is now a pastor in the United States, raised in Korea by a very harsh mother, beaten, kept out of school, living almost like a child on the street. She could not forgive. The Lord told her, "The very fact that she brought you into the world is already reason enough to be grateful to her." She forgave, brought her elderly mother to the United States and cared for her to the end.

4. "One Thing You Lack"

The young man answers with confidence: "Teacher, I have observed all these things from my youth." That is beautiful, the pastor acknowledges. People who live this way, visibly to everyone, do exist, even if they are rare.
The Japanese translation read that day says that Jesus "felt compassion for him" (the World English Bible says "loved him," Mark 10:21). As she meditates on this verse, she imagines Jesus looking at that radiant face, already knowing, since he knows the past and the future, what choice this young man was going to make.
Jesus does not merely name the lack. He gives a concrete remedy: "Go, sell whatever you have, and give to the poor, and you will have treasure in heaven; and come, follow me."
The young man's face falls. He goes away sorrowful, "for he was one who had great possessions." His torment begins at that moment.
The pastor reminds us that this world is a training ground. We were made to praise God, worship him, meet him and know him. Meeting him early in life is a blessing. As we fight sin with the help of the Holy Spirit, we are transformed little by little: God's heart becomes our heart, his joy our joy, his plan our plan.

5. Treasure in Heaven

Entering heaven is essential, but how we live here matters too. Every time we obey from the heart what the Lord asks of us, it is set aside as treasure in heaven. This is not only for pastors or leaders, but for everyone.
To illustrate this treasure, the pastor also mentions images of heaven, several of which she presents as things she has heard: clothing given according to the praise offered on earth (she points to Isaiah 61:3), tears of repentance or compassion turned into precious stones, dwellings closer to or farther from Jesus.
Giving to the poor, for the young man, meant transferring his fortune from his earthly safe to the "bank of heaven." Here, money disappears when we die, passes to others or gets stolen. Up there, nothing is lost. Helping those in need around us is how we store up treasure in heaven: "This is not a parable, it is really a principle, this is how it works."
The young man was not simply rich, he was very rich. His fortune probably came from his family, it did not belong entirely to him, and giving it away would have changed how people saw him and provoked opposition from his relatives. He stayed stuck in his hesitation, unable to decide.

6. What You Hold Instead of God

"Children, how hard it is for those who trust in riches to enter into God's Kingdom!" It is easier for a camel to go through a needle's eye than for a rich man to enter into God's Kingdom (Mark 10:24-25). At that time, wealth was seen as a sign of God's blessing, hence the disciples' amazement.
There are probably no great fortunes in the congregation, the pastor remarks, but that does not mean "this doesn't concern me." Each person can hold on to one thing they cannot let go of, which does not please God.
It may be a child you make your reason for living or your security for later, parents you count on to settle everything, money, your reputation, your knowledge, your network of relationships. Saying "I believe in God" while leaning on something other than him closes the door of the kingdom.
A simple test: when a problem arises, do you first run before God to pray, or do you first think, "How much do I have in my account?" or "I'll call so-and-so"? If you find something, let it go today and ask the Lord for the decision he is waiting for from you.
She cites Jessica Yoon, who was to go to Africa with her husband for God's work, leaving behind her only daughter. She wept with worry. The Lord told her, "Tear her out of your heart and entrust her to me." She understood that her daughter had taken a place in her heart greater than God, and she gave her fully back to the Lord. The tears sometimes came back, and God understands that, but she told herself again, "I have entrusted her to the Lord, he is her Father and her Bridegroom."
Jesus looks at his disciples and says, "With men it is impossible, but not with God, for all things are possible with God" (Mark 10:27). What our efforts cannot do, God does when we lean on him.

7. Leaving Everything for Love of Jesus

Peter begins to list: "Behold, we have left all, and have followed you." The pastor enjoys the scene: "I left this, I left that, I even left my boat!" Jesus makes no comment.
By the values of the time, the young man, probably a Pharisee or a Sadducee according to her, was respected, whereas rough-tempered fishermen did not meditate on the law day and night. Yet they are the ones who left everything to follow Jesus.
Everything we own here will eventually disappear: a fire, a theft, our death, and it passes to others. When we follow Jesus, he gives us at each step what we need, and what he gives allows us to store up treasure in heaven.
The key point is in verse 29: leaving things behind "for my sake, and for the sake of the Good News." It is not only about giving up, but about doing so out of love for Jesus. Your family and your belongings remain precious. But if someone close to you says, "It's God or me," you choose God.
It hurts at the time. But God sees your love and your obedience, and he gives back to you those you love, transformed, to praise God with you. Jesus promises a hundredfold right now, "with persecutions," because this world is under the influence of Satan, and eternal life in the age to come.
"But many who are first will be last; and the last first" (Mark 10:31). Those who were respected then will be counted among the least, and the fishermen who left everything will reign with the Lord.

Key Takeaways

The kingdom opens to those who receive it with the simple heart of a child.
The ten commandments remain God's will. Jesus brings them down to the heart, and the Holy Spirit makes us able to keep them.
A single thing held back in place of God is enough to block your walk: money, a child, parents, a reputation, a network.
What is given and obeyed out of love for Jesus becomes treasure in heaven, which nothing can steal.
What is impossible for people is possible for God: it is by leaning on him that you can let go.

Personal Application

Today, what is your "one thing," the one you hold tighter than God?
The last time a problem came up, who or what did you turn to first?
Is there anger, envy or an attachment in your heart that you need to repent of this week?
What is the Lord concretely asking you to give or to place in his hands?
If someone close to you opposed your obedience, whom would you choose, and why?

Verses Cited

Frequently Asked Questions

What did the rich young man in Mark 10 lack?

He had kept the commandments since his youth, but he could not let go of his great wealth to follow Jesus. For Pastor Ruth, the one thing he lacked was trusting God more than his possessions: he left sad because he had great possessions.

Do the ten commandments still apply to Christians?

Yes, answers Pastor Ruth: the God of the Old Testament and the God of the New Testament are the same God. Jesus even deepened these commandments by aiming at the heart, anger, lust, envy. We cannot keep them by our own strength, but the Holy Spirit helps us, and when we fall, we repent and get back on the road.

What does it mean to "leave everything" to follow Jesus?

It is not only giving things up, it is leaving them for the sake of Jesus and the Gospel, out of love for him. Your family, your belongings and your relationships remain precious, but when they stand against your obedience, you choose God. Jesus promises to give back a hundredfold, with persecutions, and eternal life in the age to come.