Joshua is the one who leads Israel across the Jordan into the Promised Land.
Moses brings the people out of Egypt and through the wilderness, but he does not enter the land. Joshua completes the passage. He is the warrior-successor, the one who carries the people from promise into possession.
The crossing of the Jordan repeats and fulfills the crossing of the Red Sea. The first crossing is liberation from bondage. The second crossing is entrance into inheritance. Between them lies the wilderness: testing, purification, law, and preparation.
In the Western Mystery Tradition, Joshua represents the threshold after initiation. It is not enough to be freed from Egypt. The soul must also cross into the land of its calling. Jericho, the Jordan, the conquest, and the division of the land all belong to the symbolism of spiritual inheritance. Joshua is the Knight after the Disciple has been formed in the wilderness. He is courage in service of promise: the active force that enters the Kingdom after the old generation has passed away.