The Unflinching Calculus of Command Text: Deuteronomy 31:23
Introduction: The Folly of the Self-Made Man
We live in an age that worships at the altar of the self-made man. Our heroes are the entrepreneurs who "pulled themselves up by their bootstraps," the inspirational speakers who tell us to "unleash the power within," and the politicians who promise a future built on nothing more than our collective human ingenuity. The modern world is a grand conspiracy to convince every man that he is his own god, the captain of his own soul, and the architect of his own destiny. This is the ancient lie of the serpent, repackaged for a secular age, and it is a damnable folly.
The man who appoints himself to a task is a charlatan. The man who promotes himself is a fool. The man who relies on his own strength is a vapor. True leadership, the kind that can stand against the howling gales of opposition and the crushing weight of impossibility, is never self-generated. It is always, without exception, received. It is bestowed. It is commissioned.
This is the bedrock principle we see at the great transition point in Israel's history. The colossal figure of Moses, the lawgiver, the prophet who spoke with God face to face, is about to depart the scene. For forty years, he has been the singular, monumental leader of this stiff-necked people. And now, he is to be replaced. By what? By a committee? By a democratic vote? By a leadership seminar? No. He is replaced by one man, Joshua, and that man's authority comes not from the people below, nor from within himself, but from the God above. This is a direct assault on every democratic and egalitarian idol of our time. God's kingdom is not a republic; it is a kingdom. And the King appoints His officers.
The commissioning of Joshua is not a quiet suggestion. It is not a pep talk. It is a divine investiture. It is the formal, legal, and spiritual transfer of authority from one man to another, under the direct command of God Almighty. What we have in this single verse is the essential calculus of all godly leadership: a divine summons, a divine command, a divine task, a divine promise, and a divine presence. If any one of these elements is missing, the entire enterprise is nothing more than wood, hay, and stubble, destined for the fire.
The Text
Then He commissioned Joshua the son of Nun and said, “Be strong and courageous, for you shall bring the sons of Israel into the land which I swore to them, and I will be with you.”
(Deuteronomy 31:23 LSB)
The Divine Initiative: "He Commissioned"
We begin with the source of all legitimate authority:
"Then He commissioned Joshua the son of Nun..." (Deuteronomy 31:23a)
The "He" here is Yahweh Himself. While Moses has already given a public charge to Joshua in the hearing of the people (Deut. 31:7-8), this is the direct, unmediated word of God to His new general. This is crucial. Joshua's authority does not ultimately derive from Moses' endorsement, as important as that was. It comes directly from God. Moses was the instrument of the commissioning, but God was the author. This protects the office from being a mere matter of human succession, like a king passing a crown to his son. This is a divine appointment.
To commission someone is to grant them a commission, a formal document of authority to perform a particular task. It is a legal and military term. A soldier is not a soldier because he feels like one, or because he bought some fatigues at the surplus store. He is a soldier because he has been duly sworn in and commissioned by the proper authority. Joshua is not leading Israel because he is the most charismatic, or the most popular, or because he won an election. He is leading Israel because God Almighty pointed His finger at him and said, "You."
This is the death of all spiritual presumption. No man takes this honor to himself (Heb. 5:4). Pastors are not pastors because they are gifted speakers; they are pastors because God has called them and the church, through the elders, has confirmed that call. A man who appoints himself to the ministry is a wolf. A man who stays in the ministry for his own ambition is a hireling. The first and most fundamental question for any leader is not "Am I able?" but "Am I sent?" Joshua was sent.
The Divine Command: "Be Strong and Courageous"
With the commission comes a command that is both a requirement and an enablement.
"...and said, 'Be strong and courageous...'" (Deuteronomy 31:23b)
This is not a suggestion to try and muster up some positive feelings. This is a command in the imperative. God does not say, "I hope you feel brave." He says, "Be brave." This is striking because it treats courage not as an emotion, but as a duty. It treats strength not as a natural endowment, but as an act of the will grounded in obedience.
Our modern therapeutic culture treats fear as a medical condition to be managed. The Bible treats fear, in this context, as a sin to be mortified. The fear that paralyzes us from obeying God is a form of unbelief. It is a practical atheism that believes the giants in the land are bigger than the God in heaven. Joshua had seen what this kind of fear does. He and Caleb were the only two spies out of twelve who came back with a good report. The other ten spread fear, the people rebelled in fear, and an entire generation died in the wilderness because of fear. Fear is not a trifle; it is a deadly poison.
But how is one to obey such a command? The strength and courage required are not generated from within. They are the logical and necessary consequence of believing the rest of the verse. God never issues a command without providing the grace to obey it. The command to be strong is predicated on the promise that follows. You are to be strong in the Lord, and in the power of His might. Your courage is not based on an assessment of your own resources, but on an assessment of your Commander's resources. The question is not, "Do I have what it takes?" The question is, "Does God have what it takes?"
The Divine Task and Promise: "You Shall Bring... the Land Which I Swore"
The command is tied to a specific, monumental task, which is itself rooted in an ancient promise.
"...for you shall bring the sons of Israel into the land which I swore to them..." (Deuteronomy 31:23c)
The task is clear: lead the invasion of Canaan. This is not a mission of peaceful coexistence. It is a holy war, an act of divine judgment against the Amorites whose iniquity was now full (Gen. 15:16). Joshua is to be the instrument of God's wrath and the agent of God's promise. He is to dispossess the wicked and give the land to God's people.
But notice the certainty of the language. It does not say, "You shall attempt to bring them in," or "If you try really hard, you might succeed." It says, "you shall bring." This is a statement of settled fact. The outcome is not in doubt. Why? Because the entire mission rests on a prior, unshakeable foundation: "the land which I swore to them."
This oath goes all the way back to Abraham (Gen. 12, 15, 17). God swore a covenant oath to give this land to Abraham's descendants. Joshua's entire military campaign, therefore, is simply the outworking in history of a promise made in eternity. Joshua's job is not to make the promise happen, but to act in faith on the promise that is already as good as done. God's reputation is on the line, not Joshua's. The success of the mission depends on the faithfulness of God, not the cleverness of Joshua. This is what liberates a leader from the crushing burden of results. Our task is faithfulness; the results belong to God.
The Divine Presence: "And I Will Be With You"
Finally, we come to the engine that drives the whole enterprise, the promise that makes all the other promises possible.
"...and I will be with you." (Deuteronomy 31:23d)
This is the ultimate promise. This is the heart of the covenant. This is everything. Without this, the commission is a death sentence, the command is a mockery, and the task is an impossibility. With this, the commission is an honor, the command is a joy, and the task is a guaranteed victory. The presence of God is the ultimate reality.
What does it mean for God to be "with" Joshua? It means His power, His wisdom, His protection, and His favor will attend Joshua's every step. When Joshua commands the Jordan to part, it will be God's power. When the walls of Jericho fall, it will be God's power. When the sun stands still at Gibeon, it will be God's power. Joshua is simply the visible agent of an invisible, omnipotent King. The presence of God with Joshua means that to oppose Joshua is to oppose God Himself.
This is the great secret of the Christian life. We are not called to live for God, but to live with God. We are not called to work for God in our own strength, but to have God work through us in His strength. The great commission given to the church echoes this same pattern. We are given a task: make disciples of all nations. We are given a promise of authority: "All authority in heaven and on earth has been given to me." And we are given the foundational promise of presence: "And behold, I am with you always, to the end of the age" (Matthew 28:18-20).
The Greater Joshua
The story of Joshua is a glorious one, but it is a shadow. Joshua, son of Nun, did bring the people into a promised land, but he could not give them the ultimate rest. They were still beset by enemies, and they ultimately fell into sin and were exiled from that same land. The first Joshua was a type, a forerunner, pointing to the true and better Joshua.
The name Joshua is the Hebrew Yeshua. In Greek, it is Iesous. Jesus. Our Lord Jesus is the ultimate fulfillment of this commissioning. He was commissioned by the Father from all eternity to bring God's people, not into a patch of dirt in the Middle East, but into the promised land of eternal life, into the very presence of God.
He was commanded to be strong and courageous, and He was. He set His face like flint toward Jerusalem, toward the cross, the ultimate battle. He did not flinch. He did not fear.
He had a task: to conquer sin, death, and the devil. And the Father declared with certainty, "He shall not fail or be discouraged till he has established justice in the earth" (Isaiah 42:4). His success was guaranteed because it was based on the sworn oath of the Father.
And the Father was with Him. At His baptism, the Father declared, "This is my beloved Son, with whom I am well pleased." Throughout His ministry, Jesus could say, "He who sent me is with me. He has not left me alone, for I always do the things that are pleasing to him" (John 8:29).
Because the greater Joshua was faithful in His commissioning, we who are in Him are now part of this great campaign. We are called to take the gospel into every corner of the world, to tear down strongholds, and to claim the nations for Christ. The task is impossible. The enemies are giants. But the commission is from God. The command is to be strong in Him. The promise is based on His eternal oath. And the presence of the risen Christ is with us, always, to the very end of the age.