Gospel Courage for Feeble Saints Text: Isaiah 35:3-4
Introduction: The Christian Duty of Not Freaking Out
We live in an age of managed panic. Our secular overlords believe that the best way to govern the populace is to keep them in a perpetual state of low-grade, and sometimes high-grade, anxiety. Whether the crisis of the moment is a novel virus, the climate, or the latest manufactured outrage, the goal is the same: to make you fearful. A fearful man is a controllable man. An anxious man is easily herded. And so the world offers its two-part solution: first, here is a terrifying problem that should make you tremble; and second, here is our godless, government-run program that will save you from it, provided you surrender just a few more of your liberties.
Into this cauldron of institutionalized fear, the Word of God speaks a bracing and contrary command. The Christian life is not a life of cowering, but of courage. It is not characterized by trembling knees, but by a firm stance. This is not because Christians are naturally stoic or because we have our heads in the sand, oblivious to the real dangers of the world. No, it is because our strength and our courage are not sourced in ourselves or in our circumstances, but in the character and promises of our God. We are commanded to be strong, not because the threats are not real, but because God is more real.
The prophet Isaiah is speaking to a people who had every worldly reason to be discouraged. They were facing the threat of Assyria, the promise of exile, and the reality of their own sin. Their hands were limp, their knees were feeble, and their hearts were hasty and anxious. They were, in short, a lot like us. And the solution God gives them through the prophet is the only solution that has ever worked. It is the gospel. It is a command to be strong, rooted in a promise that God Himself is coming. This is not a call for bootstraps religion. It is a call to look away from your own weakness and to look to the coming of your God, who comes not with gentle platitudes, but with vengeance and salvation.
This passage is a potent tonic for the discouraged believer. It is a divine command to take heart, and it provides the non-negotiable, theological reason for that courage. Our God is not a distant, deistic clockmaker; He is a God who intervenes, who judges His enemies, and who saves His people.
The Text
Strengthen limp hands, and give courage to the knees of the stumbling.
Say to those with an anxious heart, “Be strong, fear not. Behold, your God will come with vengeance; The recompense of God will come, But He will save you.”
(Isaiah 35:3-4 LSB)
A Ministry of Encouragement (v. 3)
We begin with the practical command given to the faithful remnant.
"Strengthen limp hands, and give courage to the knees of the stumbling." (Isaiah 35:3)
This is a command that is picked up in the New Testament, in Hebrews 12, after a long discourse on the faithfulness of God through trial. "Therefore, strengthen the hands that are weak and the knees that are feeble" (Heb. 12:12). This is not first a command for self-help, but a command for mutual ministry. Who is to do this strengthening? Those whose hands are not, at the moment, limp. Who is to do this encouraging? Those whose knees are not, at the moment, stumbling.
The Christian life is a corporate affair. We are tied together in one body. When one part of the body is weak, the other parts have a duty to support it. This is practical, applied theology. When you see a brother whose hands are hanging down, whose spiritual energy for his work has failed him, you have a job to do. You are to come alongside him and strengthen him. When you see a sister whose knees are knocking in fear or uncertainty, you are to speak courage to her.
Limp hands signify an inability to work, to fight, to hold on. When a man's hands are limp, he has given up. He has dropped his sword, his trowel, his tool. He has concluded that the task is impossible, the opposition too great. Feeble knees signify an inability to stand firm, to advance, or even to hold one's ground. A man with weak knees is easily pushed over. He is unstable in a battle. This is a picture of a people on the verge of collapse and rout.
And what is the tool for this strengthening? It is not found in verse 3, but in verse 4. The tool is the Word. We do not strengthen others with hollow optimism or by telling them to just try harder. We strengthen them by speaking specific, theological truth to them. The ministry of encouragement is a ministry of reminding. We remind one another of what is true, especially when the circumstances are screaming lies at us.
The Content of Courage (v. 4a)
Verse 4 provides the script. It tells us precisely what to say to the faint-hearted.
"Say to those with an anxious heart, 'Be strong, fear not...'" (Isaiah 35:4a)
The target audience is identified as "those with an anxious heart." The Hebrew is literally "the hasty of heart." This is someone whose mind is racing, whose thoughts are scattered, who is jumping to fearful conclusions. Anxiety is a sin, and it is a particularly debilitating one. It is like a steering wheel in a shopping cart that a toddler holds onto, giving him the illusion of control, but it isn't connected to anything. Worry accomplishes nothing except to reveal our functional atheism in that moment.
The command given to them is twofold: "Be strong, fear not." This is one of the most common commands in all of Scripture. God is constantly telling His people not to be afraid. And He does this, not by downplaying the danger, but by magnifying Himself. The solution to fear is not the absence of threats, but the presence of God. We must learn to distinguish between the wrong kind of fear and the right kind. The fear of man is a snare, and it is the beginning of folly. The fear of the Lord is the beginning of wisdom. If you fear God rightly, you will fear nothing and no one else. Perfect love, which flows from a right relationship with God, casts out the craven fear of punishment and the anxious fear of man (1 John 4:18).
So, we are to speak this directly. "Be strong." This is not a suggestion. It is an imperative. And it is not a strength that is drummed up from within. It is a strength that is received by faith in the promise that is about to be delivered. It is the strength that comes from knowing who is on your side.
The Reason for Courage (v. 4b)
The command to be strong would be cruel and empty if it were not immediately followed by the reason. The gospel is not just a command; it is an announcement. It is news.
"Behold, your God will come with vengeance; The recompense of God will come, But He will save you." (Isaiah 35:4b)
Here is the bedrock of our confidence. Notice the word, "Behold." It's a call to look. Stop looking at your limp hands. Stop looking at your wobbly knees. Stop looking at the terrifying headlines and the menacing enemies. Look here. Behold. Fix your gaze on this reality.
And what are we to see? "Your God will come." This is the essence of the gospel hope, from Genesis to Revelation. God is not static. He is not an absentee landlord. He comes. He intervenes in history. This promise of coming finds its ultimate fulfillment in the incarnation of Jesus Christ. God came. And in the second coming, God will come again.
But notice how He comes. He comes with two things in His hands: vengeance and salvation. Our modern, sentimentalized version of Christianity is often embarrassed by the idea of God's vengeance. We want the salvation without the vengeance. We want the cuddly Jesus, but not the Jesus with a sword coming out of His mouth. But the Bible presents them as two sides of the same coin. You cannot have one without the other. God's salvation of His people is, by necessity, an act of war against that which oppresses them, namely, sin, Satan, and the world system that is in rebellion against Him.
Vengeance is not sinful, personal revenge. Vengeance belongs to God (Rom. 12:19). It is the execution of perfect justice. It is the setting of all things right. The word "recompense" reinforces this. It means a repayment. God will repay wickedness. This should be a profound comfort to the people of God. Your suffering is not unnoticed. The injustices you endure are not forgotten. God keeps meticulous books, and the day of reckoning is coming. The wicked will not get away with it. This truth doesn't lead us to bloodthirsty glee, but to a settled confidence that justice will prevail, which frees us from the burden of taking it into our own hands.
And the final clause is the glorious result for us: "But He will save you." The same coming that brings terror and judgment to His enemies brings deliverance and safety to His children. His vengeance is our salvation. When Christ came the first time, He came to save us by absorbing the vengeance of God against our sin in Himself on the cross. He took the recompense we deserved. When He comes the second time, He will bring the final vengeance against all who have not obeyed the gospel, and He will bring the final installment of our salvation, the redemption of our bodies and the establishment of the new heavens and the new earth.
This is why we can be strong. This is why we need not fear. Because our God is coming. He is a warrior God who fights for His people. He is a just God who will settle all accounts. And He is a saving God who has promised to bring us safely home.
Conclusion: Look and Live
The logic of the Christian life is right here. The state of our hearts, hands, and knees is directly connected to the object of our gaze. If we look at ourselves, we will find weakness, anxiety, and every reason to stumble. If we look at the world, we will find chaos, threats, and every reason to fear.
The command, therefore, is to look away. To behold. To fix our eyes on the coming of our God. He is not a tame God. He is a God of vengeance and recompense. The cross is the greatest display of this, where His wrath against sin and His love for sinners met in that glorious, terrible collision. God's justice was satisfied, and our salvation was secured.
So when your hands feel limp, you are not to stare at them in despair. You are to preach this verse to yourself. When your heart is hasty and anxious, you are to command it to be still and behold your God. He is coming. He will repay your enemies. And He will save you. This is not a pious wish. It is the ironclad promise of the sovereign God of the universe. Therefore, be strong, and fear not.