The Book of Joshua recorded Israel's victory over her enemies through trust in and obedience to God. The Book of Judges shows the defeat of the nation by its enemies from without and within due to refusal to trust and obey God.
"No book in the Old Testament offers the modern church as telling a mirror as this book. From the jealousies of the Ephraimites to the religious pragmatism of the Danites, from the paganism of Gideon to the self-centeredness of Samson, and from the unmanliness of Barak to the violence against women by the men of Gibeah, all of the marks of Canaanite degeneracy are evident in the church and its leaders today. This book is a wake-up call for a church moribund in its own selfish pursuits. Instead of heeding the call of truly godly leaders and letting Jesus Christ be Lord of the church, everywhere congregations and their leaders do what is right in their own eyes."379
"The principle theme of the Book of Judges is Failure through Compromise' which is in contrast to the main theme in the Book of Joshua which is Victory through Faith.'"380
"The Book of Judges illustrates both God's justice and His grace--justice in punishing sin and grace in forgiving sin."381
The course of Israel's decline progressed in a descending series of cycles. She went from blessing to apostasy to discipline to repentance to deliverance to rededication to blessing, etc. Her deterioration grew out of spiritual apostasy and manifested itself in moral degeneracy, political disorganization, and social disintegration.
"So the Book of Judges ends with a miracle. How after chapters 19-21, indeed, after chapters 1-21, can you account for the fact that there is still an Israel? It can only be because Yahweh wished to dwell in the midst of his people in spite of its sin. It can only be because Yahweh's grace is far more tenacious than his people's depravity and insists on still holding them fast even in their sinfulness and their stupidity. Nor is he finished raising up saviors for them (Acts 13:23)!"382
Joshua and Judges, therefore, give proof positively and negatively of how the basic principles affecting the relationship that God intends people to enjoy work out in national and personal life. The Pentateuch revealed these principles.