Sadly, the next generations after Joshua made bad choices. As often happens, they thought they knew better than their parents.
All that [faithful] generation also were gathered to their fathers. And there arose another generation after them who did not know the LORD or the work that He had done for Israel. And the people of Israel did what was evil in the sight of the LORD and served the Baals [Canaanite idols]. And they abandoned the LORD, the God of their fathers, who had brought them out of the land of Egypt. They went after other gods, from among the gods of the peoples who were around them…. So the anger of the LORD was kindled against Israel, and He gave them over to pluderers, who plundered them. And He sold them into the hand of their surrounding enemies. (Judges 2:10-12, 14)
It took just one generation for God’s people to forget all that had been learned, to lose all they had gained. From that point, the history reported in Judges reminds us of a seesaw. The people don’t want God and His rules, so they tip the seesaw away from God. They fall so hard that they get hurt. When their enemies make life unbearable, they call on God for relief. God is gracious and He sends a leader— called a “judge”—to rescue them. They come back up to accept God’s help. But when life improves, or when the judge dies, they fall again and suffer the same consequences, which causes them to cry to God again, and so on. This cycle of falling and rising, rebellion and restoration, continues throughout Judges and characterizes much of Israel’s history (Psalm 106:34-48; Nehemiah 9:27-31). Judges closes with this summary: “In those days there was no king in Israel. Everyone did what was right in his own eyes” (Judges 21:25).