Let's start with Heaven. Following this "everything is spiritual" premise, we will have to reject that Heaven is a physical place. Which makes sense anyway, since heaven is just a word for sky and the God of the Bible is a sky god (versus an earth goddess). If God, in the Bible, is in Heaven, it just means that he's "out there" while we're "down here." But if we're speaking spiritually, the sky can't be a physical place either, so we have to locate it inside ourselves. "Inside" sounds physical too, but we all know it isn't. Even the word "feelings" sounds physical, but isn't. "You hurt my feelings." Or my favorite: "You broke my heart." We speak spiritually/metaphorically all the time, but -- in spite of our everyday use of figurative language -- the metaphors of the Bible are taken by many as physical facts. But we're going past that idea today, for fun. So now we have it that Heaven is a place, seemingly out of reach, inside us, where God lives. Hold that thought.
Let's go to Hell. Again, if we're following our premise that the Bible is a spiritual book, Hell isn't a physical place either: no fire (except as metaphor), no brimstone (except as metaphor). So it too must be a place inside us, traditionally (though not Biblically) a place where the Devil lives.
So what about the Devil and God himself? Are they spiritual also? We're sticking with our premise, so yes. They too fit within the symbolism of our spiritual life. You know the standard cartoon image of the little devil on one shoulder and the little angel on the other telling you what to do? Are they physical? No. Are they real? Yes.
And God as a character is the most important symbol of all, a symbol pointing to the beautiful and unexplainable and unnamable mystery of life itself. But the only way to get to him is to go through the symbol. If you get stuck on the symbol, you haven't reached God.
If you want to go beyond this premise game, stop listening to idiot me, and listen to an expert, then listen to Jesus himself: "No one can see the Kingdom of God unless he is born again." Now listen to the response to this statement from Nicodemus, a religious guy: "How can a man be born when he is old? Surely he cannot enter a second time into his mother's womb to be born." Now listen to Jesus slapping his head in frustration.
Jesus goes on to say, "Flesh gives birth to flesh, but the spirit gives birth to the spirit." When Jesus said to drink his blood and eat his body, everyone got upset because they thought he was asking them to be cannibals. I could give example after example of Jesus getting frustrated when someone doesn't understand that he's speaking metaphorically, which is the only way to speak spiritually (and almost any other way). If only more people would pay attention in literature class.
This Nicodemus section, by the way, is from a very famous book and chapter of the Bible: John 3, in which Jesus says that whoever believes in him will have "everlasting life," a slightly better translation of that phrase being "the life of the future." Because the "future" he's talking about is the immediate future for anyone who wants to shed their old ways of thinking and accept this new way. That's what the Kingdom of God is. When Jesus "ascends" (stop! remember to think spiritually!) to "Heaven," he's going to that "place" where he says anyone can also go right now. The only thing you have to do to enter the Kingdom of God is to realize it's already here. It's a mindset. It's a metaphor. And it's the opposite of religion.
I know it's comforting to put everything off until the distant future, especially if you think that future won't arrive in your lifetime or be available until you're dead. It's a procrastinator's dream. And I know that it's not too sexy to think of these fantastic Biblical images simply as metaphor. The Apocalypse is transformed from an explosive World War III in the year 4000 into a spiritual destruction of your old way of thinking. The Garden of Eden is no longer a beautiful paradise with two naked supermodels, but instead it's just an inner place you can return to once you get past your limited conception of life as merely a series of "good" things and "evil" things. (Note that I'm greatly simplifying interpretations of these strong images; they will resonate differently for everyone, and to fully absorb them is to have no words for them at all.)
But thinking this way is also liberating. Everything begins to make logical sense, and you don't have to feel silly for believing in water shooting out of stones or sticks turning into snakes. If you become a good enough student of spiritual literature (the Bible is good, but don't stop there), the metaphors open up to you and you will understand them (and not understand them, which is often even better) the more you think about them, and they can actually change your life in a practical way: your inner life affecting your life in action which affects the world around you which affects the world at large.
If you weren't thinking this way already, give it a shot for about a week or two and report back to me with your findings. Good luck.