Strong in the spiritual struggle (chapter 6)

Paul wanted the Ephesians to be strong in the Lord.  They were to put on the armor of God so that they could fight off the devil.  The fight was not against flesh and blood, but against principalities, cosmic powers, and heavenly evil spiritual armies.  Therefore, they had to have all the spiritual armor to fight this battle.  In this struggle with the spiritual evil, they had to stand firm.