1 John 4:4

Little children (believers, dear ones), you are of God and you belong to Him and have (already) overcome them (the agents of the antichrist); because He who is in you is greater than he (Satan) who is in the world (of sinful mankind).

Jesus came to this world to redeem humanity, bringing salvation and authority for the believer.  We are to use our authority to rule and reign in our lives.  The Holy Spirit inside the born-again believer is our direct connection to the throne of God.  Just as we are to exercise our faith, we use our authority.