05 How to Build Your Life on a Rock, not Sand

by Krisan Marotta | Mar 4, 2026 | 01 Podcasts, Start Strong

In the conclusion of the Sermon on the Mount in Matthew 7:12-29, Jesus describes two paths. He warns us to choose wisely because one path leads to life and the other to destruction. He also discusses the Golden Rule and what it means to build your life on the rock of his teachings.

What Is a Worldview?

Everyone has a worldview, even if they have never used the word.

A worldview is the lens we use to answer life’s biggest questions: Who am I? Why am I here? What is right? What is real?

Think of your worldview as a pair of contacts. We put them on and forget them, but they change how we see the world. A worldview is not something we think about. It is something we think with. Just as we view the world through the glasses we wear, we view the world through our worldview.

In Chapter 5 of Start Strong: A New Believer’s Guide to Christianity, we explore what it means to see the world through a Christian lens, a worldview where God is at the center, not us. It reshapes how we see ourselves, how we relate to others, and how we live.

Today we return to the book of Matthew, looking at the conclusion of the Sermon on the Mount.

Two Great Themes of the Sermon on the Mount

The Sermon on the Mount contains two great themes which we can summarize with two Old Testament verses:

Theme 1: “You shall love your neighbor as yourself” (Leviticus 19:18).

Theme 2: “There is a way that seems right to a man, but its end is the way to death” (Proverbs 16:25).

The two great commandments, to love God and love our neighbor, flow from the worldview Jesus describes. Let’s explore what it means to live with God at the center and why Jesus ends this profound sermon with a warning.

The Kingdom Message

Prior to this sermon, Matthew only told us two things about what Jesus was teaching in his early ministry. In 4:17, Matthew said Jesus was teaching, “Repent, for the kingdom of heaven is at hand.” And in 4:23 he was proclaiming the gospel, or the good news, of the kingdom.

Jesus is teaching that God has promised to send his Messiah, his anointed one, to establish God’s rule over all the earth. This is the kingdom of God. The Messiah will defeat all sin and rebellion and rule over God’s people in peace and righteousness forever.

Jesus preaches the good news that the day of the Messiah’s kingdom is coming upon us. He is here to announce and explain it. However, if you want to find a place in that kingdom you need to repent.

The first-century Jews who heard this message must have been perplexed. Their religious understanding was largely shaped by the Pharisees, who were the primary teachers in their synagogues. You can imagine their response: “Wait, Jesus, we are the chosen people of God. We have been taught by these great students of the Scripture, the Pharisees. Why do we need to repent? We’re ready for the kingdom now.”

Jesus answers that question in this sermon. He describes the people who will be forgiven on judgment day and receive eternal life in his kingdom. The entire Sermon on the Mount is about one topic: Who will be accepted by God?

The Golden Rule: Love Your Neighbor as Yourself

Matthew 7:12: “So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets.”

This famous verse is known as the Golden Rule. To love your neighbor is to act for your neighbor’s benefit. What kind of feelings you have is irrelevant. It is how you act that counts.

To love your neighbor as yourself is to put yourself in your neighbor’s place, figure out how you would want to be treated in that situation and then do that.

Later in Matthew Jesus defines the two great commandments.

Matthew 22:34-40: But when the Pharisees heard that he had silenced the Sadducees, they gathered together. And one of them, a lawyer, asked him a question to test him. “Teacher, which is the great commandment in the Law?” And he said to him, “You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment. And a second is like it: You shall love your neighbor as yourself. On these two commandments depend all the Law and the Prophets.”

The Golden Rule is another way of stating the second great commandment: love your neighbor as yourself. When Jesus says “for this is the Law and the Prophets,” he is telling us this is of fundamental importance.

Of all the things God has told us, love God alone and love your neighbor as yourself are two of the most fundamentally important. These truths stands behind much of the Law and the Prophets. The law forbids such things as murder, theft, vengeance and taking advantage of the poor. All those things are wrong because they represent a refusal to love our neighbors as ourselves. They represent a refusal to act toward others as you would have them act toward you.

Jesus starts this verse with “therefore.” Your translation might have “so.” I think that “therefore” goes back beyond the previous section to the whole sermon. Based on everything he has said in this sermon, therefore do unto others as you would have them do unto you.

This is a fundamental moral truth that we must embrace. It lies behind much of this sermon.

That truth is this: There is a God, and you are not him. You are no more or less important than your neighbor. God made you both in His image. When you submit yourself to God, you embrace the truth that your neighbor’s welfare is as important as your own.

One of my mentors called this the principle of the mirror. When you look at your neighbor, it is like looking in a mirror. In some significant way, you are seeing yourself. Obviously, there are differences, but in some fundamentally significant ways, you are seeing someone just like you.

Why can’t I congratulate myself as righteous if I have not murdered anyone but have merely hated them? Hatred is inconsistent with loving your neighbor as yourself. See: Matthew 5:21-26 Anger & murder

Why can’t I appeal to “an eye for an eye” as a guide for how I treat people? Taking vengeance is inconsistent with loving your neighbor as yourself. See: Matthew 5:38-42 An Eye for an Eye

Why can’t I love my tribe and hate my enemies? Hating your enemies is inconsistent with loving your neighbor as yourself. See: Matthew 5:43-48 Love your enemies

Why is it so important that we are merciful (The Merciful (Matthew 5:7) and forgiving people (Matthew 6:12-15 The Lord’s Prayer: Forgiveness)? When we look at our neighbor, we are looking in a mirror in the sense that we are seeing another sinner like ourselves. If we admit that we need mercy, then we understand that to condemn our neighbor is to condemn ourselves because we are in the same situation.

Why can’t we judge and condemn others (Matthew 7:1-5 Log in your eye)? When we look into the face of someone who has sinned against us, we are looking in a mirror. We are seeing a sinner just like us. The standard that condemns the other person also condemns us.

These are all statements from the Sermon on the Mount. The principle of loving my neighbor runs throughout this sermon.

What the Golden Rule Is Not

Let me clarify two things about the Golden Rule.

1. The Golden Rule is not a way to have good relationships and an ordered society.

Treat other people well and then other people will treat you well. Sometimes practicing the Golden Rule does produce good relationships, but not always. Sometimes you act kindly toward people and they turn around and mock you.

That is not what Jesus is saying. Jesus is not saying be nice so that others will be nice to you. If anything, he is saying be kind regardless of how others treat you. He is focused on our motivations.

Our job is to love our neighbor as ourselves. How the other person responds is not the issue. They may respond well. They may not. Our responsibility to act for their benefit remains the same.

A big part of what it means to be a sinner is that I am thinking about me more than I am thinking about you. As a sinner, I act in the way that benefits me most. Economics often assumes that principle. We act in our best interest, often with a selfish disregard for the needs of others.

Jesus tells us to put ourselves in the other person’s place. How would we evaluate our behavior if we were on the receiving end instead of the giving end? The Golden Rule is fundamental to living a godly life.

2. the Golden Rule is not meant to stand by itself. It is a fundamental principle, but it does not tell us everything we need to know.

How do I decide what is in my neighbor’s welfare? That can get complicated. Sometimes I cannot figure out what is in my own best interest, let alone someone else’s.

Figuring out how to act in any situation takes wisdom, the kind of wisdom Jesus spells out in this sermon. This whole sermon gives us a picture of people who are trying to live by the Golden Rule.

The Golden Rule does not give us specific guidelines for specific situations. Instead, it is like a compass. It gives us a direction from which to approach any situation. Like a compass, the Golden Rule lets us evaluate whether we are on the right path. It does not give us specifics for every circumstance.

The Golden Rule summarizes one of the main themes in this sermon: love your neighbor as yourself. The rest of the verses wrap up the second major theme.

The Two Roads

I called the Golden Rule the principle of the mirror. I call this second theme the two roads. Or, as expressed in Proverbs 16:25: “There is a way that seems right to a man, but its end is the way to death.”

The Pharisees would have agreed in principle: there are two roads before us. One leads to life in the kingdom of God and one leads to destruction.

The Pharisees called the people of Israel to obey the law of God. They studied and preached the Law. That is why it is shocking that the Sermon on the Mount spends so much time saying, do not be like the Pharisees. Today we are used to thinking of them as the “bad guys,” but the Pharisees were the religious role models of the day. They were the good guys to the Jews of Jesus’ day.

Throughout this sermon, Jesus describes those who are on the right road, those who will inherit a place in the kingdom of God. The problem is, contrary to popular belief, the Pharisees are on the wrong road.

God’s people are poor in spirit (Poor in Spirit (Matthew 5:1-3), merciful (The Merciful (Matthew 5:7), forgiving, and repentant. But the Pharisees were often self-righteous and judgmental (Matthew 5:17-20 Surpassing the Pharisees). God’s people seek treasure in heaven, life in the kingdom of God (Matthew 6:19-24 Treasures in Heaven). But the Pharisees sought the treasures of this life, including the praise and approval of their peers (Matthew 6:1-6; 6:16-18 Giving, Praying & Fasting).

From beginning to end, Jesus lays out two distinct paths. Blessed are the poor in spirit, but woe to those who are rich in spirit. Blessed are those who mourn, but woe to those who laugh. We talked about these ideas in the Beatitudes in the last podcast.

On the one hand are those who are growing in humility and mercy and seeking life in the kingdom of God. On the other hand are those who are self-satisfied and hungry for the riches of this world.

Jesus urges them to take the path that leads to life and not be fooled by the piety of the Pharisees.

Four Variations on the Theme

In Matthew 7:13-29 we see four variations on the theme of the two roads.

The broad way and the narrow way.
False prophets with bad fruit and true prophets with good fruit.
Those who call Jesus Lord who will not enter the kingdom and those who call Jesus Lord who will.
Those who build on the sand whose house will be destroyed and those who build on the rock whose house will stand.

We need to understand these metaphors in light of the rest of the Sermon on the Mount.

If we read these verses alone, Jesus is not specific. He does not say how to choose the narrow gate. He does not tell us what bad fruit looks like. He does not say what the will of God is that the person who calls Jesus Lord should be doing. He does not tell us how to find the rock to build on or how to avoid the sand.

He does not have to answer those questions here because he already answered them in the rest of the sermon. He already told us who will inherit eternal life. He told us who the blessed ones are. He told us what kind of righteousness we need to have, and it is not like the Pharisees’. He told us what to set our hearts on when we pray. He warned us against the path of the hypocrites and urged us to seek the treasures of heaven.

Now he impresses upon us the need to choose the right path. He has told us the essential issues of faith and how to find life. He gives us four metaphors to drive the point home.

The Narrow Gate

“Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many. For the gate is narrow and the way is hard that leads to life, and those who find it are few.” (Matthew 7:13-14)

He tells us two things.

One path leads to life and one path leads to destruction.
Those who choose the way to life are in the minority.

Presumably the reason most people do not choose the road to life is because they do not want to. They do not view it as a good option. The wide versus narrow image tells us that the road to life is not as attractive as the road to destruction.

The road to life requires repentance and humbly admitting that we are evil. We must pursue love and mercy because we see ourselves in the same boat as other sinners. We must endure the hostility and persecution of those who reject Jesus. We must seek the true treasure found in the kingdom of God rather than the false treasures of this world.

By nature, we are foolish, blind people. Taking the road to life requires waking up and opening our eyes. It requires admitting we were wrong. It requires turning from the lies of this world and turning back to God.

That is not easy and it can be costly. Making that choice can cost us our family and friends and even our life.

Jesus is reminding us: yes, the road can be difficult. It may not look attractive at first glance. It may look wrong because few are taking it. But it is the road to life. If you want life, you have no other option.

Beware False Prophets: Recognize Them by Their Fruit

Beware of false prophets, who come to you in sheep’s clothing but inwardly are ravenous wolves. You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles? So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus you will recognize them by their fruits. (Matthew 7:15-20)

Wolves are the classic enemies of sheep. One of the shepherd’s main jobs was protecting the sheep from wolves. In the gospel of John, Jesus describes himself as the shepherd who does not abandon the sheep to the wolves. See: Understanding Jesus as the Good Shepherd (John 10:1-21)

In this analogy, we are the sheep. Someone who looks like a sheep comes among us. This person looks just like us. But under the disguise he is a ravenous wolf there to destroy.

Jesus warns that people will come who claim to know the road to life. They will claim to have a message from God. Yet they are not from God. They are not promoting the word of God. They are destroying it.

Later in Matthew, Jesus will use similar and much harsher language to describe the Pharisees.

Matthew 23:13 But woe to you, scribes and Pharisees, hypocrites! For you shut the kingdom of heaven in people’s faces. For you neither enter yourselves nor allow those who would enter to go in.

Matthew 23:15 Woe to you, scribes and Pharisees, hypocrites! For you travel across sea and land to make a single proselyte, and when he becomes a proselyte, you make him twice as much a child of hell as yourselves.”

This is not gentle language. He calls them blind guides. They presume to lead others to the truth, but they are blind themselves.

Throughout history we have seen people who claim to proclaim the word of God, but who destroy the people of God and lead them astray.

How do you tell the difference between false prophets and true prophets? You know them by their fruit. The true prophets will be poor in spirit, humble, merciful, peacemakers, and seeking life in the kingdom of God. The false prophets will be worldly, focused on the pleasures of this world, self-righteous, judgmental, and unloving. See: 7 Key Marks of False Teachers

“Lord, Lord” Is Not Enough

Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness. (Matthew 7:21-23)

The new thing here is the language of those who call Jesus Lord. Up to this point in the sermon he has been contrasting the Pharisees, the hypocrites, and the Gentiles with people who follow him. Now he focuses on the people who call him Lord. Even among those who claim to follow Jesus, some will be on the wrong path.

Living a religious life is no guarantee that you will be in the kingdom. As Jesus says in this sermon, your righteousness must exceed that of the Pharisees. They were pious and religious men, yet they were on the wrong path. That kind of self-righteous piety is not enough.

The real evidence is whether you seek to love God and to love your neighbor as yourself. If you practice lawlessness, the fact that you call Jesus Lord means nothing.

The big question is what Jesus means by doing the will of the Father in verse 21. In 7:23 he describes those who will be condemned as workers of lawlessness. What does he mean?

We need to understand these verses in light of the entire sermon. He means exactly what he has been describing since Matthew chapter 5.

The one who does the will of God is the one who has embraced the truths he has been laying out in this sermon. Coincidentally, those are the truths I laid out in my book, which was heavily influenced by this sermon.

Humbly repenting before God, being merciful, hungering for holiness, seeking first the kingdom of heaven, counting on the promises of God, seeking to follow what God says is true, seeking to love God and to love our neighbors as ourselves.

The lawless ones are those who, like the Pharisees, claim to follow the law of God, but use the law to pursue their own self-righteous and worldly gain.

The issue is not whether you name the name of Jesus and can get nine out of ten questions right on a theological exam. The question is whether you are the sort of person who has saving faith and a new worldview.

This kind of person is not necessarily perfectly obedient and courageous in every situation. We are sinners. But we are honest sinners. As we go through life, we face basic questions: Who am I counting on? What am I hoping for? What do I think is really true? What is truly important? Where is life to be found?

When we face those situations, we choose to follow God. We embrace and seek to live out the truths of God and to count on his promises. Am I willing to see myself as the sinner I am? Am I really praying for and seeking forgiveness and rescue from my sin?

It is also important to realize that not all the so-called teachers of Jesus are worth listening to. There are lots of ways to be a “Christian” that do not actually match the teaching of Jesus. Numbers are not an indication.

The fact that a teacher runs a megachurch or has worldwide followers is not a divine stamp of approval. We are called to be wise, to be discerning, and to look at whether this person lines up with what we saw in the Sermon on the Mount.

There are a lot of books and self-help philosophies that present themselves as Christian. Be discerning.

Naming the name of Jesus and calling him Lord is not the real test. You have to mean it in a profound way. The test is whether you live like what Jesus said is true. That includes all the things he has been teaching in this sermon. It is not enough to claim to believe. You must live your life in light of what you believe.

Building on Rock or Sand

Everyone then who hears these words of mine and does them will be like a wise man who built his house on the rock. And the rain fell, and the floods came, and the winds blew and beat on that house, but it did not fall, because it had been founded on the rock. And everyone who hears these words of mine and does not do them will be like a foolish man who built his house on the sand. And the rain fell, and the floods came, and the winds blew and beat against that house, and it fell, and great was the fall of it. (Matthew 7:24-27)

The image is vivid. The poet Edna St. Vincent Millay wrote a two-line poem that captures it:

“Safe upon the solid rock the ugly houses stand: Come and see my shining palace built upon the sand!”

That is the point. It does not matter how big and grand the palace is. If it is built on sand, it will not last. That is how we are to picture our lives in this world. Are you building on the rock or the sand?

Have you founded your life on the solid, eternal truths of the gospel or not? If you have, God will ensure that you withstand all the hurricanes that come at you. You will find life and blessing in the end.

How do you build on the rock? Jesus tells us: you hear and you let it change your life. You act on the kinds of things Jesus has been teaching in this sermon. You hear and embrace the truths he has proclaimed, and you seek to live in light of those truths.

This sermon contrasts those who take the road to life with those who take the road to destruction. Repentance instead of stubbornness. Humility instead of arrogance. Mercy instead of vengeance. Hunger for righteousness instead of hunger for wealth and power. Seeking the approval of God rather than the approval of men. Forgiving rather than judging.

Why This Sermon Matters

Notice how much importance Jesus gives to the Sermon on the Mount.

If you act on what Jesus just said, you are building on the rock and your house will stand. If you do not act on what Jesus just said, you are building on the sand and your house will fall. That is how important this sermon is.

The Sermon on the Mount shows us the way to the narrow gate, the road to life, and where to build our house. Like the gospel, the Sermon on the Mount shows us how to find life.

Even though Jesus does not spell out the cross here or the specifics of God’s plan for salvation, he is talking about the heart of the believer. He is describing people who have saving faith.

Saving Faith and a Changed Worldview

When we hear that Jesus is the Christ who died for our sins and was raised from the dead, why do we believe it? Because by the grace of God, we have hearts that are humble.

We have come to experience a major shift in worldview. We no longer see ourselves as the center of the universe and more important than our neighbors. We realize God is the center of the universe and we human beings are equal before him. Therefore we strive to love God with all our being and we strive to love our neighbors as ourselves. We believe the gospel is true.

We hold four convictions of saving faith: We know that we are sinners. We know that we need God’s mercy. We know that God owes us nothing and we long to be free from our sins. We know that this world cannot truly satisfy or fulfill us because it is corrupted by sin and death.

When we hear the good news that the King has come and will come again to establish his kingdom over all the earth and to vanquish sin and death, we shout for joy. We welcome all the good news of the gospel because our hearts are willing to admit that we need it. This sermon describes the hearts of people who will respond to the gospel.

Choose the Narrow Way

To choose the narrow way is to choose to believe the gospel. Those who are poor in spirit, merciful, humble, and so forth are the ones who embrace and believe the gospel. To them belongs the kingdom of heaven.

The Sermon on the Mount calls us to choose the narrow path to life by loving God, loving our neighbor, and building our lives on the rock of Jesus’ teachings. Those who do will inherit the kingdom of heaven.