1. Circumcision is needed to begin the fight (1-9)

They had crossed the Jordan and were about the attack Jericho. That generation had never been circumcised. They needed spiritual preparation before embarking on their mission. God told them to take flint knives and circumcise all the males. In doing so they were renewing their commitment to God and their covenant with him. This was rolling away the reproach of Egypt (9). They were renouncing idols and committing to the Lord.

2. Thanksgiving and reverence to God (10-15)

After the Israelites were healed, they celebrated the Passover. They celebrated the grace of God, who saved them from slavery and brought them to this point. On the way to Jericho, Joshua met an angel. He fell face down in reverence towards God. He recognized the place as holy ground. Thankfulness and a sense of holiness are needed to fight any spiritual battle.