Here's a video with the song played backwards with no lyrics. Watch it and see if you hear a Satanic message. By the way, you might have to listen to the whole song, since some of the people who claim there is a hidden message don't have it matching with every line of the song being played forwards. Let me know if you hear anything?
In closing, I think this song is actually pro-Chrisitian and anti-Satan. The song the way I interpret it is about a lady who has it all, beauty, riches, and fame, and she thinks she on her own abilities can buy her salvation. However, she finds that salvation can't be bought. The store to do so is closed. There's still time for everyone who is on her path to get on to the other path. But then again, who can tell with this song? It could mean anything? There's even a line about when all is one and one is all. That certainly sounds like new-age mysticism. Here is what I do know. In Genesis 28 Jacob has a dream of a stairway that connects heaven and earth and in John 1:51 Jesus references this dream and essentially says, "I am the Stairway to Heaven." When you look at Christianity and what the Bible teaches, it is the only religion which says the way to salvation can't be bought. It's the only free religion in the world. It's the only religion in which God has stepped down and has done it all for your salvation. The Stairway has come down to us and Jesus is that Stairway and He is a Rock that doesn't roll.