This isn't an article about the afterlife.
This is an article about writers, especially fantasy writers, creating their own representation of Heaven and Hell in their work. You can build a setting so wonderful your readers will wish they can buy a ticket there for their next vacation, or so terrible they will shiver with fear.
"On earth there is no heaven, but there are pieces of it." --Jules Denard
Although I use Heaven in this article, for the sake of contrast, another way of putting it is Home. It's a place where your characters feel loved and accepted, usually a place of peace and truth and beauty. The beauty does not have to be extravagant or perfect. A cracked vase with a single wildflower can be more beautiful than a silver urn overflowing with roses. It's the heart put into the place that makes it special.
The importance of Heaven is twofold. First, it gives the audience some place to care about and to feel safe in. When that place is threatened, the audience feels that tension. Another use of Heaven is to manifest ideals and themes. It can be a utopia, a place to aspire to.
Some famous representations of Heaven include Hobbiton, Rivendale, and Lothlorien in the Lord of the Rings, Hogswarts in the Harry Potter series, Shangri-La in Lost Horizon. But my favorite versions of Heaven probably come from the writings of Laura Ingall Wilder, who drew such a vivid portrait of the landscape of the American pioneer, it inspired a thousand games of make-believe.
"We are each our own devil, and we make this world our hell." --Oscar Wilde
Hell, by contrast, is any setting comprised primarily of pain and misery and dread. It is a place where natural human relationships are strained, perverted, or broken. It may be superficially beautiful, but it is rotten to the core. Whereas Heaven inspires the audience's love, hell provokes fear.
Hell is the ultimate obstacle. It will test your protagonist on every level. It serves as an object of dread; if Heaven is what your protagonist seeks to gain, Hell is what they want most to avoid. That said, as an author, you'd do well to toss them into Hell at least sometimes. If the hero's don't confront Hell, they don't deserve Heaven.
Hell is probably easier to write, since we have many more real world examples and since, while people might disagree on what Heaven looks like, we all have a pretty good idea of Hell. Popular examples include Mordor in Lord of the Rings, the arena in The Hunger Games (where the games are played), and, well, Hell in Dante's Inferno. My most frightening vision of Hell was in George Orwell's 1984. I had nightmares for a week.
1. Draw on your own loves and fears
"To different minds, the same world is a hell, and a heaven." --Ralph Waldo Emerson
Heaven is usually built on love, hell on fear.
When you start to draw these places up, you should begin with yourself, what you love, what you fear. If you simply steal the trappings of other people's visions of heaven and hell, without bringing in your own emotions, you'll be left with a dull facade.
For example, if you love animals, incorporate that into your version of heaven. I, personally, like art, culture, and history, so into the pot it goes. In The Changelings, I drew upon my experiences in Japan to create a festival that, for me, represented the heavenly aspect of that particular group of people.
As far as fears, I tend to draw on failure, rejection, brainwashing, loss of control, and things of that nature. I find that cult environments play heavily in my version of hell.
Don't overdo it. Don't try to throw in everything at once. Also be careful to make sure your love and fears can appeal to a wider audience. I have a phobia abut butterflies, but I doubt I could evoke fear with a horde of raging Monarchs.
"Go to Heaven for the climate, Hell for the company." --Mark Twain
This is a bit obvious, but Heaven and Hell are settings.
Not necessarily physical ones, though. If you're literally doing Heaven and Hell, you're dealing with the afterlife. Or you could do a dream world or a virtual reality. In cases where you're not dealing with physical limitations, you may still want to set some specific ground rules, so that your writing isn't all over the place.
If you are creating a physical landscape, what sort of environment? Land, sea, sky, underground? Hot, cold, temperate, humid? Wild or civilization? City or country? Woods, mountains, grass, swamps, river, lakes, volcano, islands?
Rather than picking and choosing places at random, you may want to look at the characters, ideas, and scenarios you already have in your head. For example, if your character is a mermaid, Hell might be a desert or any stretch of land far from the ocean. If you know your character values freedom, Hell might be a prison.
For some reason, the strongest representations of Heaven and Hell that I've read about have some element of isolation. In Heaven, this isolation protects it from evil or corrupting influences. In Hell, this isolation helps keep the evil from running rampart; but once you're there, you can't get out.
One thing you may want to consider, then, is a barrier. It can be a physical barrier, like mountains, desert, sea, or a physical wall. It can also be something more abstract, like magic, existence on a different plane of reality, secrecy, or obscurity: no one knows about this place.
"The safest road to hell is the gradual one--the gentle slope, soft underfoot, without sudden turnings, without milestones, without sign posts." --CS Lewis
I, personally, like to know the origins of everything, whether or not I share it with the readers.
If you're only dealing with a wild, natural landscape, no further explanation might be necessary. But if there's any human (or non-human) involvement, you may want to think about who built the place and why and how.
Heaven, I like to think, is built on the foundation of love, so think about what the great passion of the builders may be. What sort of ideals did they hope to embody? What obstacles did they have to overcome and sacrifices did they have to make to create the place? Are they still working to better themselves even now?
With hell, it's a bit more complicated. Unless you have beings that are pure evil, most people don't set out to build a place of pain and suffering. So what happened? What went wrong?
You could begin with a fear. People were desperate to protect themselves, and in that desperation, they did something stupid, like hand over power to a dangerous man or shut themselves into a system they can't get out of.
It might begin as a kind of bitterness or hatred to a certain group of people that grew and grew, until it became ever more demented. It might begin as a beautiful ideal that got perverted somewhere down the line. Maybe the place was a normal city, but complacency and indifference allowed criminals to take over. Maybe greed got the better of the people.
There's all sorts of scenarios you could come up with.
"To be willing to march into Hell for a Heavenly Cause" --from Man of La Mancha
So now that you've got your Heaven and Hell, it's time to think about how your character gets to these places. One of the simplest ways is to have your character start off in either your version of Heaven or Hell. That way, one location is given right off the bat.
A person starting off in Heaven might experience a fall from grace and be ejected or they might voluntarily leave to seek out greener pastures (before discovering there's no place like home) or they might be forced away from their Heaven in order to protect it, rather like a soldier might.
They might be violently ripped away: captured, kidnapped, enslaved, orphaned. Or it might be that Heaven gets destroyed from the beginning and they might have to seek a new paradise or build one from scratch.
On the other hand, they might start off in Hell. An orphan or slave might, through brains, cunning, skill, spirit, daring, or sheer luck, find himself propelled out of his horrible situation. Or, perhaps he, like his Heaven counterpoint, is forced out, due to war or other external forces. Maybe he's rescued from his situation.
Another option is for a character to stay in the same basic place, but have either that place, or their perception of that place, change. Even Heaven can become Hell, if taken over by bad management, as Hogwarts was under Voldemort. Or perhaps the character starts off thinking they're in Heaven or in Hell, but as they see more of the world, they get a new perspective.
Perhaps a great catastrophe comes to the place. War, for example, can make even the most peaceful place into a Hell. Or it could be a natural disaster or (in the case of virtual reality) maybe some bug in the system.
If, however, a character actually has to seek out Heaven or Hell, consider why. Hell usually pops up as an obstacle the character must go through in order to get to Heaven, but if the character intentionally seeks it out, there must be a reason.
In classical myth, heroes make trips to the underworld (Hell) in order to retrieve a loved one's soul or to seek the advice of one long dead. There can be valuable treasures in Hell, as well, enough to make the trip seem tempting. Or perhaps they want to destroy Hell and can only do it from the source.
The last thing to consider is that the character may never actually enter Heaven or Hell. The places may exist as an aspiration or as a threat, and maybe the mere mention of them is enough.
5. What Can Threaten Heaven?
"If you're going through hell, keep going." --Winston Churchill
Heaven, at least the kind found on earth, usually has a sense of fragility to it. Whatever is good and peaceful and loving and beautiful can always be destroyed. One of my favorite passages from Lost Horizon sums up this fragility nicely:
"It came to him that a dream had dissolved, like all too lovely things, at the first touch of reality; that the whole world's future, weighed in the balance against youth and love, would be light as air. And he knew, too, that his mind dwelt in a world of its own, Shangri-La in microcosm, and that this world was also in peril. For even as he nerved himself, he saw the corridors of his imagination twist and strain under impact; the pavilions were toppling; all was about to be in ruins."
In this case, it takes only a shift in the hero's perception, that causes the whole thing to collapse. One generation might build their ideal, only for the next generation to reject it. Passions cool, causes are abandoned, community ties become too much work. People leave.
Of course, it might, more directly, be attacked.
Hell, like any good enemy fortress, likes to appear unassailable, but, unless you're writing a depressing Dystopia in the vein of 1984, it usually has some weakness built into it. If Hell is built on deceit and people discover the truth, that power is broken. If it is built on fear and people find courage, that power is broken. If it is built on hatred and people forgive, that power is broken.
Change can happen anywhere and in the blink of an eye.