Satan & Evil-Outstanding Talk By The Most Reverend Venerable Fulton Sheen (Archbishop & Theologian)
The power of Satan is, nonetheless, not infinite. He is only a creature, powerful from the fact that he is pure spirit, but still a creature. He cannot prevent the building up of God’s reign. Although Satan may act in the world out of hatred for God and his kingdom in Christ Jesus, and although his action may cause grave injuries—of a spiritual nature and, indirectly, even of a physical nature—to each man and to society, the action is permitted by divine providence which with strength and gentleness guides human and cosmic history. It is a great mystery that providence should permit diabolical activity, but “we know that in everything God works for good with those who love him” (CCC #395).
Do not be deceived. Satan is real and we must resist him, strong in our faith. However, do not be so terrified that you forget that GOD, His angels, and the grace HE bestows on us are more powerful and that GOD limits what demons can do. Trust GOD; call to HIM; frequently recite the 91st Psalm. Be sober and watchful and stay distant from the once-glorious fallen angels we rightly call demons.