The Great Leveling Text: Isaiah 40:3-5
Introduction: The Royal Road of God
The world thinks of progress in terms of building taller towers, bigger economies, and more complicated machines. But when God announces His arrival, when He prepares to move in power, His first order of business is not construction, but demolition. It is not about building up man's proud towers, but about tearing them down. It is about leveling the ground. This is the great paradox of the kingdom: the way up is down, the way in is through the narrow gate, and the way for the King is a road made low.
This passage from Isaiah is one of the great hinges of redemptive history. It is the announcement, after a long period of judgment and warning, that God is about to do something new. He is coming to His people. And when a king travels, the roads must be prepared. Eastern monarchs would send heralds and engineers ahead of the royal procession to make the journey smooth. They would fill in the potholes, knock down the inconvenient hills, and straighten out the winding paths. It was a massive undertaking, a display of the king's power and importance. All obstacles must be removed before the king arrives.
Isaiah is picking up this royal imagery and applying it to the coming of Yahweh Himself. But the terrain He is concerned with is not the Judean wilderness. The valleys that need filling are not literal depressions in the dirt, and the mountains that must be brought low are not made of granite. The wilderness is the human heart, and the landscape that needs leveling is the social and spiritual order of mankind. This is a prophecy about a radical reordering of all things. It found its initial fulfillment in John the Baptist, who was the literal voice crying in the wilderness, preparing the way for Jesus Christ. But its ultimate fulfillment is nothing less than the establishment of Christ's kingdom over all the earth.
This is a postmillennial sledgehammer. It is a promise that the gospel is not a quiet, private affair. It is God's earthmoving equipment. It is designed to flatten the pride of man, to lift up the humble, and to create a great, level plain where the glory of the Lord can be revealed for all to see. This is not a description of the end of the world, but of the world's conversion. It is the blueprint for the Great Commission.
The Text
A voice is calling,
“Prepare the way for Yahweh in the wilderness;
Make smooth in the desert a highway for our God.
Let every valley be lifted up,
And every mountain and hill be made low;
And let the rough ground become a plain,
And the rugged terrain a broad valley;
Then the glory of Yahweh will be revealed,
And all flesh will see it together;
For the mouth of Yahweh has spoken.”
(Isaiah 40:3-5 LSB)
The Herald's Cry (v. 3)
The prophecy begins with a sound, a summons that breaks the silence.
"A voice is calling, 'Prepare the way for Yahweh in the wilderness; Make smooth in the desert a highway for our God.'" (Isaiah 40:3)
All four Gospels identify this voice with John the Baptist, and rightly so. He was the great transitional figure, the last of the Old Testament prophets, whose entire ministry was this one task: preparation. But what does it mean to prepare the way for Yahweh? It means repentance. John's message was simple and sharp: "Repent, for the kingdom of heaven is at hand!" (Matthew 3:2). To prepare the way for God is to get right with God.
The "wilderness" and the "desert" are crucial here. They are places of testing, of judgment, but also of new beginnings. Israel came through the wilderness to enter the promised land. John preached in the wilderness to announce the coming of the true Promised Land, Jesus Christ. The wilderness is the human condition apart from grace. It is dry, barren, and hostile to life. God's highway does not go around the desert; it goes straight through it. The gospel does not come to those who have it all together, but to those who are spiritually destitute. It is in the wilderness of our sin and rebellion that the call to prepare comes.
This preparation is not a humanistic project of self-improvement. We are not commanded to build the highway, but to prepare the way for it. It is God's highway. He is the one who does the real construction. Our job is to clear the debris. Repentance is the act of getting our junk, our pride, our self-righteousness, and our pet sins out of the path of the divine bulldozer. It is agreeing with God about the state of the landscape. It is admitting that the road is a mess and that we cannot fix it ourselves.
The Great Reordering (v. 4)
Verse 4 describes the specific engineering work that must be done. This is the heart of the leveling project.
"Let every valley be lifted up, And every mountain and hill be made low; And let the rough ground become a plain, And the rugged terrain a broad valley;" (Isaiah 40:4 LSB)
This is social and spiritual language, not geological. What are the valleys that must be lifted up? They are the humble, the poor in spirit, the outcasts, the nobodies of this world. In the economy of God's kingdom, those who are low will be exalted. Think of Mary's Magnificat: "He has brought down the mighty from their thrones and exalted those of humble estate" (Luke 1:52). The gospel comes as good news to the poor, to those who know they are in a spiritual valley and have no way to climb out. The highway of God lifts them up.
And what are the mountains and hills that must be made low? They are the proud, the arrogant, the self-sufficient, the powerful who trust in their own strength. They are the institutions of men that set themselves up against the knowledge of God. They are every form of humanistic pride, whether it is the pride of the Pharisees in their religiosity or the pride of the modern secularist in his supposed reason. The gospel is an offense to the proud because it requires them to come down. You cannot receive grace while standing on a mountain of your own achievements. You must be brought low. The cross is the great mountain-leveler.
The rough ground and rugged terrain refer to everything that makes the way difficult. These are the crooked dealings, the perverse habits, the injustices, the complexities of sin that twist and distort human life. The gospel makes things straight. It brings a radical simplicity. It calls for straight talk, honest dealings, and a life that is not a tangled mess of excuses and rationalizations. The highway of God is a straight road. It is a plain path. The Christian life is not complicated; it is just hard. It is hard because it requires us to submit to this divine leveling.
The Unveiling of Glory (v. 5)
Verse 5 gives us the grand purpose of this entire project. Why go to all this trouble? Why this radical re-engineering of the human landscape?
"Then the glory of Yahweh will be revealed, And all flesh will see it together; For the mouth of Yahweh has spoken." (Isaiah 40:5 LSB)
The ultimate goal is the manifestation of God's glory. The glory of God is the public display of His infinite worth and beauty. When the ground is level, when the pride of man is brought low and the humble are lifted up, then there is a clear line of sight. Nothing obstructs the view. And what do we see? We see God in His majesty.
This is a promise of global, visible success for the gospel. "All flesh will see it together." This is not talking about every individual being saved, but about a universal, undeniable manifestation of God's glory in history. It is a promise that the kingdom of Christ will not be a hidden, secret society. It will become the defining reality of human civilization. The knowledge of the glory of the Lord will cover the earth as the waters cover the sea (Hab. 2:14). This is the engine of Christian optimism, of a robust, world-conquering postmillennialism. The work of leveling is happening now, through the preaching of the gospel and the discipling of the nations, and the result will be a worldwide display of God's splendor.
How can we be sure of such an audacious claim? "For the mouth of Yahweh has spoken." This is the bedrock of our confidence. It does not rest on our abilities, our strategies, or the shifting polls of public opinion. It rests on the performative, world-creating, irreversible Word of the living God. When God speaks, reality rearranges itself. He spoke light into existence. He spoke this promise of a leveled world and a revealed glory. And it will be done.
Conclusion: Your Place on the Highway
This ancient prophecy is a present reality. The road crew is on the job. The voice is still crying, not from the Judean desert, but from pulpits and street corners and dinner tables all over the world. The call is the same: "Prepare the way for the Lord."
This means you must first allow the leveling work to be done in your own heart. Are you a mountain of pride, trusting in your own goodness, your own intellect, your own respectability? Then you must be brought low. You must come down from that mountain and stand on the level ground at the foot of the cross, admitting you have nothing to offer. Or are you a valley of despair, crushed by your sin, convinced that you are too low for God to reach? Then you must be lifted up. You must believe the good news that Christ came to seek and to save the lost, to exalt the humble, and to fill the empty with His grace.
Once this work has begun in you, you are enlisted onto the road crew. The Great Commission is our mandate to take this leveling project to the ends of the earth. We are called to be voices, crying in the wilderness of our culture, calling for repentance. We are called to apply the gospel to every rough place, every crooked system, every proud institution. We do this with confidence, not because the task is easy, but because the outcome is certain. The mouth of the Lord has spoken. The highway is being built, the King is coming, and His glory will cover the earth.