Satan Will Always Be Around, Even After You've Attained Nirvana

I had a powerful insight last night. I have long studied Buddhism, and the basic idea behind Buddhism is that once you achieve enlightenment, there is no one that can take that away from you; you live forevermore in a state of Nirvana. I believe that this would be true, but it must be emphasized: Nirvana would be a state of mind; the external world wouldn't change when you'd attained Nirvana, what would change would be your way of seeing it. You would have become enlightened. Once you'd reached this state, there would be no one or nothing that could take that away from you.

Then I combined this with an insight from Judaism/Christianity: Satan is an inseparable part of this world. You can't remove Satan from this world. He and God will always stand in opposition, doing battle. The world without Satan in it is unfathomable. 

Buddhism of course preaches multiple lifetimes. One lifetime leads into the next, ad infinitum. Whatever you achieve spiritually in one lifetime you carry into the next. This includes Nirvana, of course. Once you are set in Nirvana, you are set in it for Life. But that doesn't change the fact that Satan still holds sway in this world. Death will never be pushed into the background; it will always stand as a recurrent hiatus from life. Even when you've attained Nirvana- and can see BEYOND life-and-death, you still have to pass through the cycle- as seen from the unenlightened's superficial perspective. You still have to face temptations; life is still a challenge; it's still trying. But you now have a certain way of seeing things that makes it all worthwhile....