Joshua, Old Testament

The Children of Israel were destined, under Moses, to wander in the Wilderness for a full forty years. This was the consequence of their lack of faith in God's ability to deliver them safely into Canaan, where they would reestablish themselves in Abraham's old home as the new national power.
But getting to the Promised Land and actually taking possession of it were two different things. It was true that the Israelites had only to look out on the ground day after day to see that God was on their side. How else could the daily provision of manna ("What is it?") be explained? But the spies sent to check out the Canaanites and their defenses were not helpful. All but two felt that conquering these people might be too great a task. And the people were inclined to agree, because almost no one really wants war.
God's response was to slam the door to the Promised Land on all the remaining Israelites who had begun their lives in Egypt as slaves. They were condemned to live out their days putting one foot in front of another crisscrossing the desert until, one by one, they had all died. Only then could they take up the issue of the conquest of Canaan again.
And one of the two optimistic spies, Joshua, was to succeed Moses, who was also kept from crossing over. Entering the land was more celebratory than military, but it wasn't all good news. One thing that made it clear that things were now to be different was that the daily manna ended.
Another, and much more daunting, was the command to Joshua to clear the land of all the native peoples. It might not be necessary to slaughter them all, but, one way or another, they were to be removed.
It is said that we can receive no command from God that cannot be obeyed, but this one would prove to be a test simply beyond the will of the Israelites to fulfill. The members of the twelve tribes had each staked out territory to occupy, and quickly did so. But each tribe found a way to peacefully deal with the locals in ways that fell well short of God's command.
He had known that, just as living among the Egyptians had a negative effect on His people, appeasing the Canaanites would produce similar results. Sure enough, intermarriage and the partial adoption of the beliefs of idol worshipers did have a negative effect.
Joshua did all he could over a long period of time, but was finally reduced to simply leaving it up to the people to choose for themselves the objects of their worship, making it clear that he intended to serve the Lord, as he always had.