nocturne got it right. The point is that Satan was CONFINED to the earth. And, he's really mad now! The date thing may be wrong, may be right, I'm not sure that matters a whole lot. I used to get into terrble rows with my history instructors over dates. They were so anal about them, claiming that dates are the "vertebrae" of history. I felt that understanding the "flow" of history was vastly more important than the specific whens, and that fussing over whether England was invaded in 1050 or 1051distracted from the issue. Most of my history professors were left unfazed as they handed back my tests with the red ink all over them.
You won't get any scriptures to refute what your mother has said, unless they are made up or misapplied. So, you got two choices, you can throw up your hands and state the whole thing is BS and close your mind to it, or, you can take the modern "realistic" approach and look at this world and tell yourself that it's really a wonderful place to be. That it's really great, and, why, the people in the Thebes of 839 BCE lived exactly like we do today, i.e. with the threat of suitcase nukes, and aerosol anthrax, and runaway Aids, and mass starvation, and pandemics, and poisoned environment. I mean, didn't James Cooleridge extol the virtues of Prozac and Wellbutrin as everybody and everything at that time was just as depressing as it is today? Satan and his demons being confined to the earth? What a joke! There's no proof of that! Go ahead, prove it, I dare you.