Why did God give humans free will instead of angels?
God made the human race with an indwelling attribute of will so they could be objects of His love and either respond to that love or reject it. Angels could not respond in that way. Satan was brought on the scene so that humans could exercise that choice; otherwise, there would be no will exercise.
Les explains that God's purpose was to have objects of His love who could voluntarily return love. Since angels couldn't respond, God made the human race with the indwelling attribute of will to either respond to His love or reject it. That is why Satan was brought on the scene—so humans could exercise that choice; otherwise there would be no will exercise. Les connects this to Ephesians 3:10, where the church makes known the manifold wisdom of God according to His eternal purpose, addressing why God did it all.