Satan is defeated to the person that is right with God,for spiritually they are conquerors,for greater is He that is in you,than he that is in the world,and resist the devil,and he will flee from you,but not defeated as far as causing problems in the natural realm for Christians,but still on a leash and can only go so far,but he is not defeated in punishment where he has no more influence in the world,and eternally damned.
Satan can still stir up trouble for Christians,as the Bible says all that will live godly will suffer persecution,and a messenger of Satan came to buffet Paul,and give him a thorn in the flesh,which God allowed to keep Paul humble.
1Co 5:1 It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife.
1Co 5:2 And ye are puffed up, and have not rather mourned, that he that hath done this deed might be taken away from among you.
1Co 5:3 For I verily, as absent in body, but present in spirit, have judged already, as though I were present, concerning him that hath so done this deed,
1Co 5:4 In the name of our Lord Jesus Christ, when ye are gathered together, and my spirit, with the power of our Lord Jesus Christ,
1Co 5:5 To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
We may have trouble in the flesh,but spiritually we will not have trouble.Maybe some people are afraid of the physical trouble,and not afraid of any spiritual trouble.