Joshua was Moses’ “minister” (v.1), the man he picked to defeat the first enemy Israel encountered (Ex.17:9-13). That made him the natural choice to succeed Moses, for Israel’s next leader would have to be a warrior to rid the Promised Land of the seven Canaanite nations (Deut.7:1). From the beginning, Moses associated himself with Joshua (Ex.24:12, 13) to prepare the Jews to accept his leadership later.
Joshua was one of the 12 men Moses sent to spy out the land, and one of only two who remembered God said they could conquer the Canaanites if they obeyed Him (Lev.26:8; Num. 13:1—14:8). So only Joshua and Caleb were allowed to live to enter Canaan (Num.32:11,12), and of them God picked Joshua to lead Israel, and Moses ordained him in Numbers 27:18-20. Then Moses charged him to lead Israel into Canaan (Deut.31:7,8), and the Jews accepted him (Deut.34:9).
Joshua and Moses were types of Christ. Moses was a type of Christ in His earthly life. He is called God’s servant (Josh. 1:1,2), as was Christ (Isa.42:1-3). Innocent Hebrew boys were slaughtered when both Moses & Christ were born. Both were meek, and both left riches behind to enrich their people. But Joshua became a type of Christ in His resurrection life when he vanquished the seven Canaanite nations, a type of how Christ in His resurrection life will vanquish the seven nations aligned with Antichrist (Rev.17:1-10).
Joshua’s name even means Jesus (cf.Heb.4:8), because both names mean “Jehovah Savior.” But Christ couldn’t be Israel’s Savior till he died for their sins, just as Joshua could not save Israel from the Canaanites until Moses died for his.
But to bring Israel into Canaan, they’d have to cross Jordan (Josh.1:2). When God parted it, as He had the Red Sea (Josh.3:17), both partings typify how the Lord will someday part them again to lead Israel into their kingdom (Isa.11:15).
In Joshua 1:3,4, God quotes what He said to Moses (Deut.11: 24) to describe a land nearly 50,000 square miles bigger than the current state of Israel. It’s the land God promised Abram (Gen.15:18), and Israel will fully possess it in the kingdom.
God knew Joshua knew the giants lived in Canaan, because he’d seen them (Num.13:33), so he told him that “not any man” could resist him (Josh.1:5), as He told Moses (Deut.7: 24). God vowed to be with Joshua (1:5), just as He promises Tribulation saints (Heb.13:5) so they won’t fear men (v.6).
Moses told Joshua to “be strong” (Deut.31:7), and God quotes that to Joshua (Josh.1:6). He meant strong in the law (Josh.1:7). Physical strength couldn’t topple the walls of Jericho, but being strong in the law would enable God to do it! Remember, He promised He would conquer Israel’s enemies “if” they obeyed Him (Lev.26:3,8; Deut.11:8).
That’s how God promised to “prosper” Joshua if he obeyed (Josh.1:7,8), by beating the Canaanites. Not letting the law depart out of his mouth (1:8) meant reading it aloud so people could hear and learn to obey it (cf.Deut.31:11,12).
God doesn’t promise to prosper us if we obey Him, but obedience is the only proper response to grace. Meditating on the Word (Josh.1:8) will help us obey, and be a good testimony to others (ITim.4:14). It will also give us the “good success” God promised Joshua (Josh.1:8). “Success” just means a termination, whether good or bad. We think of all success as good, but then to say “good success” would be redundant. If you want to come to the termination of your life and be able to say you enjoyed good success in your life, meditate on God’s Word and obey it in every area of life.
The word “dismayed” (Josh.1:9) means to lose courage (1:9 cf.10:25; IChron.22:13; 28:20; IIChron.32:7). When Paul lost his courage, he got it from the brethren (Acts 28:15). When you find you are losing yours, come to church!