Joshua received only part of the authority Moses had. Moses had spoken with God face to face (12:6–8; Deuteronomy 34:10–12). Joshua did not have that same direct access to God’s revelation.
Instead, Joshua had to seek guidance through Eleazar the priest on important matters (Numbers 27:21; compare Exodus 28:30; Leviticus 8:8). Eleazar used the priestly means of seeking God’s will.
From this time on, Israel separated military leadership from spiritual leadership. Joshua led the army, while the priest guided the people in spiritual matters.