Judges 2:12

And they forsook the LORD God of their fathers, which brought them out of the land of Egypt, and followed other gods, of the gods of the people that were round about them, and bowed themselves unto them, and provoked the LORD to anger.

After Joshua and the elders who had seen the Lord's great works died, another generation arose that did not know the Lord nor remember His works and fell into apostasy. That generation did evil in serving Baalim, forsaking the Lord God of their fathers who had brought them out of Egypt to follow the gods of the peoples round about them and bow themselves to them, mingling His worship with erroneous principles and ambitious pride, and so provoked the Lord to anger.

Their idolatry spread after they mingled and intermarried with the Canaanites. Although the revival at Bochim had been genuine, with contrition, confession, sacrifice, reformation, and forgiveness through Christ's grace, the seed of evil already sown sprang up to bear fruit.

Their sins separated them from God, so His protecting hand and strength were withdrawn, and their departure from allegiance to Him and exaltation of powers opposed to Him brought disaster, defeat, and subjection to the very nations they might have subdued, leaving them unable to prevail against their enemies. They were brought in turn into subjection to the king of Mesopotamia, the king of Moab, the Philistines, the Canaanites of Hazor led by Sisera, and to Midian with the Amalekites. In the Midian calamity the tribes east of the Jordan suffered first, when the wild desert inhabitants spread over the country from the Jordan to the Philistine plain and stripped the harvests for seven years.

The story was repeated again and again as a cycle of backsliding and chastisement through oppression. In distress the people gave heed to the Lord's reproof and confessed their sins. Then God raised up helpers and deliverers such as Othniel, Shamgar, Ehud, and Deborah and Barak, and faithful deliverers put down idolatry and freed Israel, but after a deliverer died the people gradually returned to their idols.