Satan is ruler of the world's system. God gave Adam and Eve all authority on the earth and told them to rule, to have authority, dominion, and to subdue anything that gets out of line, according to Gen 1:26. But when they obeyed the devil and ate the fruit, they not only were born again into sin, needing a savior, but they gave all their authority to Satan. (Eph 2:2) The ruler of this world Satan] is judged. (John 16:11) Look at: (John 12:31) Now is the judgment of this world; now the ruler of this world will be cast out.Our job is to enforce the completed work of Jesus and bring God's will on earth as it is in heaven.