"Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand" (Ephesians 6:13). Satan has already been judged. It happened when Christ paid the price for our sin with His death on the cross.
"Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand" (Ephesians 6:13).