The LORD your God himself will go over before you. He will destroy these nations before you, so that you shall dispossess them, and Joshua will go over at your head, as the LORD has spoken.
Joshua very much foreshadows the work of Christ and the spread of the gospel into the world. God commissions Joshua to go in and take possession of the land that God has given them. This is echoed by Jesus in the great commission: Go, disciple the nations, and I will be with you. He says, “Every place that the sole of your foot will tread upon I have given to you,” and to His Christ He says, “Ask of me, and I will make the nations your heritage, and the ends of the earth your possession,” and we are fellow heirs with Him. God tells Joshua to be careful to do all that Moses had commanded and Christ came to fulfill the law in order that the righteous requirement of the law might be fulfilled in us. God goes before them to destroy their enemies and drive out the nations before them. Again, Psalm 2 says of the Son, “You shall break them with a rod of iron and dash them in pieces like a potter’s vessel.”
At least six times in his commissioning, Joshua, as head of the nation of Israel, is told to be strong and courageous. He is leading his people to war. Theirs was a war against flesh and blood enemies, enemies they could see. Ours is a war against unseen enemies, principalities and powers, but also our own lusts and desires that war against us and draw us away from the love of God. Christ, our head, faced the battle. Because He made himself nothing, taking the form of a servant, being born in the likeness of men, His strength was not in self-reliance. His strength was in completely giving Himself over to the Father, to do His will and to love Him. He who knew no sin became sin for us. He redeemed us from the curse of the law by becoming a curse for us. He humbled himself by becoming obedient to the point of death, even death on a cross.
Everything that Christ is, everything the Father has given Him, He gives to us. The Father has given the Son all authority, to give eternal life to those who believe and the life He gives us is to know the Father. Christ gives us the word that he has received from the Father. He speaks that we might have His joy fulfilled in us. Just as He was sent to do the work of the Father, so He sends us. We are commissioned to go out in the name of Christ, the name given to Him by the Father. The glory that He had before the foundation of the world, he freely gives to us to invite us into the unity that He shares with the Father. All this so that the love that the Father has for the Son may be in us also, as Christ is in us.
“In the world,” He says, “you will have tribulation. But take heart; I have overcome the world.”