Why does God allow Satan to live? - John Piper

Satan is self destructive.  Satan will be burned up after the second resurrection. He will marshal all of the lost to try and take the city of God. God's light turns the wicked into the lake of fire. Satan and the false prophet are tossed into that fire. We need the kind Lord God in us to push Satan out of us. He opens the eyes of whoever making them to see God where he is and to see Satan wherever he is