I have question for you EyesOnZion
Luke Chapter 8
30. And Jesus asked him, saying, What is thy name? And he said, Legion: because many devils were entered into him.
31. And they besought him that he would not command them to go out into the deep.
The devils were scared to be sent to the deep. Do you think that is where the devils are located? The bottom of the ocean?
I hope I can figure out how to do this...but let me try to tackle the answer. To be honest, I haven't considered
all the ramifications of this answer, so this is just a gut response. First let me say that I don't think that the deep is the same as the ocean, per se. In order to really get a grasp, an understanding of the Ancient Hebrew cosmology is necessary. If you take all that the Bible presents about the world, you end up with a picture of the world sorta like this...
Scholars will debate some of the finer points of this chart, but generally speaking, they all look something like this. So the 'deep' is actually a separate layer below the ocean (well...sea is what they call it). Now this 'deep' is talked about in other cultures as well, especially in their creation accounts. The deep tends to represent a chaotic force where no life can exist. In some accounts, the god battles with the dragon of the deep, in others he rises out of the deep. I think that this "uninhabitable chaotic force" is a better description of the deep than attributing it to some actual locale on the ocean floor.
Where it gets tricky is the passage you mentioned about Legion. Obviously, if they were afraid of being sent there, it must be considered a real place. While the ancient Hebrews saw it as being under the sea, I'm not insistent that that's where the 'deep' is located. I mean, they also thought a wall was holding up the water in the sky, and modern science has debunked that understanding.
So if I had to take a stab at understanding that passage, I'd be inclined to say that Legion was begging not to be sent to the place of 'chaotic desolation', because that's the worst place imaginable. And while the audience of the time would have assumed that it was located underneath the ocean, I don't think the biblical text is necessarily telling us that it is located there.
But to be honest, I'm not entirely sure. Perhaps we need to give more credence to the Hebrew cosmology, or perhaps we need to consider that the spiritual realm and the spatial realm overlap. But I think we get more answers about the 'deep' from looking at how it's treated in other Ancient Near East cultures than we do trying to locate it through modern science.