we are all pieces of God's intel and Satan is like the spy who loved him so know he sends his demons to infiltrate our lives so that at the final
battle he can somehow have enough god info to alter his destiny.
Read the Book of Revelation it says Satan will be cast in the Lake of Fire to be tormented forever and ever. Satan can't change his destiny. It has
been preordained that he will fail. God will create a New Heaven and a New Earth where there will be no more evil or sin.