Because the people rebel and fear to go where God leads, they will have to spend 40 years in the wilderness, where the present generation will die out.
The spies sent into the land become fearful of the Canaanite people and bring an unfavorable report about the land (see “The Nephilim” in Introductory Issues). The people complain and ask to return to Egypt, to which God responds with a word of judgment: a 40-year stay in the wilderness, time for the present generation to die out completely. Among the spies, only Caleb was faithful and will be spared the punishment. This 40-year period marks not only a chronological interlude in the wilderness journey, but a theological one as well. The old generation will die, and God will begin anew with a new people (even a new census, chapter 26). Here we see an instance of what will become the essential biblical theme of death and renewal or death and resurrection. Sin and rebellion produces death; but out of death, God makes a new thing.