At the start of the book, Joshua is appointed as Israel's new leader, a new Moses. He commands obedience to the covenant, sends spies into the land, and brings the people of Israel through the waters of the Jordan River. The book then details a series of battles. The book is clear that these battles are not about Israel versus other nations but about God fulfilling his promise to the family of Abraham.
In the battles that follow, Israel learns the hard way to walk in covenant faithfulness. As they do, some of the Canaanites surrender, while most try to extinguish the Israelites. The justice that God brings on human evil finds unique expression in Joshua as God drives out the Canaanites. Having defeated their enemies, the people of Israel divide the land by tribe and receive final words of challenge from Joshua to remain faithful to the covenant.