Read Deuteronomy 1-3.
The name of the book means "second law". It is the second giving, or explanation, of the law by Moses to this second generation (1:5).
Here Moses takes time to recount what happened forty years before that prompted their wilderness wandering to bring them to this place. He reminded them of the events found in Numbers 13. The command was to "go up and take possession" of the land God promised to Abraham and his descendants. But the people asked for some men to go and spy out the land first. When the report came back from the spies, the nation refused to go in. Joshua and Caleb stood against their entire nation and declared that there was no reason for fear. The LORD would fight for them.
But the nation did not believe God would take care of them. They believed an evil report against God and therefore became an "evil generation" (1:35). So, they wandered around until that entire adult population died. Even then, the LORD did not forsake them. He watched over them, protected them, and cared for their needs. He fought for them as they faced opposition and war from other nations. "For the LORD your God has blessed you in all the work of your hands. He knows your going through this great wilderness. These forty years the LORD your God had been with you. You have lacked nothing" (2:7)
That previous generation did not enter and enjoy the full blessings of God due to unbelief. Moses failed as well to trust God at a crucial time. In an angry moment he, too, lost the privilege of entering the land.
Now, a new generation was poised to cross the Jordan River and do what their fathers would not dare. They needed to hear the stories again. They needed to be reminded of the mistakes of the past. They needed to be taught again the basic expectations that God had for them as a people.
The writer of
Hebrews comments on what happened to the first generation that came out
of Egypt. "So we see that they were unable to enter because of
unbelief" (Hebrews 3:19). The urging to all of us when facing
difficulties and hard roads ahead is not to question God, or to believe that
God is mad at us (1:27), but in faith-believing trust Him. "Take care,
brothers, lest there be in any of you an evil, unbelieving heart, leading you
to fall away from the living God. But exhort one another every
day..." (Hebrews 3:12-13a).