Everyone believes in something. Even Atheists. The problem arises when that something, isn’t the same thing as someone else’s something. Worse yet, when those two someones who believe in different things use the same words for them. Differences over the meaning of “god” have caused wars. There have been great upheavals when two powerful people have looked at the same ancient text and decided that it tells them radically different things about how to live.
And these are just examples from real life.
In fiction, you would think that we could come up with some truly spectacular stories about the differences between various sects. We probably could… but for the most part, we don’t.
I’ve read a lot of books, and the few that articulate different religions rarely use it as a source of tension. Most science fiction stories ignore the notion of religion all together and the fantasy stories assume that everyone in the world has the same religion. Sigh. Neither view point makes much sense in the context of human societies. Humans will disagree with each other about the meanings of life. So they will form different belief systems and from that you will get new religions. Note the plural.
When dealing with non-humans, or at least non-earth-humans, you have the same problem. Is it any easier to believe that all aliens would have the same gods as it is to believe that a planet will have an unstratified climate? Even on a dry planet where it might all be desert, the polar regions will have different temperatures than the tropical regions and mountains will be different from valleys. So why should we think that creatures who evolved on said desert planet would have the same religion if they are from a tropical mountain village as one who grew up in a polar valley? The forces they wished to control would be different. Their languages would probably have been different (at least sometime in their history) and so the names of their gods would be different. The rituals of their year would be different. They might even fight over the importance of various times of year.
So why don’t we explore this? The answer is actually rather simple. Religion is complex. There are the core beliefs, rituals, structure and governance, secondary beliefs, daily actions, and world view – just to name a few things you need to know about a religion to incorporate it into your story. So why would you want to go through all that multiple times – especially if you think that the story isn’t about the religions? It’s not being lazy so much as it is choosing your battles.
On the flip side, adding religions and their interactions can lend a depth of reality to your story that just isn’t available any other way. Nothing is so enlightening about your world as it is to have two characters with vastly different points of view describe it. Again, peek at politics for an example or two (in this election season you should find one in the first 2 minutes of any news broadcast). More specifically, look at the rhetoric around the Same Sex Marriage issue or abortion. Many of the voices on both sides of these issues claim to be Christian and yet they have polar opposite views. Look a little deeper into it and you’ll find that the voices are actually coming from different sub-sects of Christianity.
In the Middle East we see a lot of divisions in politics stemming from divisions in Islam. It would be fun as an academic exorcise to survey the participants in the Arab Spring and the other civilians in those countries about their world views. How would they differ from that of the ruling class and government forces that tried to stop them? How might that inform the kinds of strife and political movements in our made up worlds?
How much more interesting would your hero’s quest be if the antagonists were “evil overlords” but rival heroes from other cultures? Imagine that the great dragon your hero has been sent to destroy so that Fluvia, Goddess of the rains, will bless his homeland with fertile crops is, according to the people on the other side of the mountain, the embodiment of Krest, lord of the sun, who rewards his defenders with life giving light. Your hero is going to have a lot of warriors to get through before he can face the dragon, and perhaps and moral crisis to contend with if he ever stops to listen to the people over there. Or perhaps your Heroine is traveling through a region where the divine evil is a goddess, how would the people see her and her journey. Or reverse it. Hero travels where the gods are all evil and the goddesses protect her people. It could be something as simple as how you give thanks for a meal that gets your hero or heroine into trouble. “You pray before you eat? that’s blasphemy! Out of my Inn and never show your face here again!”
Taking this idea to Sci-fi, how might your characters react differently to a new technology based on their religion or world view? Some might embrace it without reservation “Oh, cool the new widget.” Others might have a problem with it. “But it is breaking the natural order of things. We can’t let anyone know we’ve created it.” Others might see it as the second coming: “We’ll make sure that everyone shall have this widget. It is the salvation of humankind.” It’s the same widget, different views on technology. Think about cloning, or stem cell research. For some these new technologies are the salvation. For others they are abominations. Any tech could be seen that way, from the right perspective. Even environmental science is falling under this diversity of perspective. While some folks see the worlds as something we live on, other insist it is something we live in. Are we lords over the world or part of it? Is it our right and prerogative to chop down the forest or are we cutting out our own lungs? Is it our right to teraform another planet so we will have space for our expanding population, or is that dangerously close to “playing god?”
Oh the fun we could have exploring all this great territory. Maybe we will.