In the battles of life, your peace is actually a weapon. Indeed, your confidence declares that you are not falling for the lies of the devil. You see, the first step toward having spiritual authority over the adversary is having peace in spite of our circumstances. When Jesus confronted the devil, He did not confront Satan with His emotions or in fear. Knowing that the devil was a liar, He simply refused to be influenced by any other voice than God's. His peace overwhelmed Satan, His authority then shattered the lie, which sent demons fleeing.
Francis Frangipane, The Three Battlegrounds (from Praying God's Word by Beth Moore)