It would be a story of tragic proportions if Satan still had the authority he gained at the Fall in the Garden.  But that’s not the end of the story.  Jesus was sent to get it all back, to redeem what was lost.

The Lord looked and was displeased that there was no justice.He saw that there was no one, he was appalled that there was no one to intervene; so his own arm achieved salvation for him, and his own righteousness sustained him. Isaiah 59:15

Jesus won back authority at Calvary.  He also achieved this by living a life without sin.  When Satan tried to tempt Him and cause Him to stumble, Jesus walked in perfect obedience, something no man could do. He became the second Adam, our representative before God, just as Adam had been initially. The identical law that brought God’s curse to our world was the same one that Jesus subjected Himself to in order to defeat it on our behalf. 

Consequently, just as one trespass resulted in condemnation for all people, so also one righteous act resulted in justification and life for all people. For just as through the disobedience of the one man, the many were made sinners, so also through the obedience of the one man, the many will be made righteous. Romans 5:18-19

When Jesus won back the authority, he turned around and gave it back to us. We are, again, God’s representatives.  So many don’t exercise it because they don’t know they have it.  Do you?  

Then Jesus came to them and said, All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age. Matthew 28:18-20