Inventing fictional religions.
As you produce your fictional world, sooner or later you will also need a belief system. This one sounds crazy, but realistically the citizens of your fictional world are going to create a religion. Author of the Gust touches briefly on the wacky ninja religion invented for that series, a religion that seems to focus primarily on performing rituals at a series of shrines. Their culture is filled with an endless array of ritualistic practices, driven by a series of documents referred to as simply sacred scrolls. Though it is not a primary story element, the series builds on the religion all through the three volumes. In the third book, the primary antagonist invents his own series of scrolls that allows him to cease control of a large portion of the ninja population. This is especially infuriating for the main protagonist, who has seen the original scrolls and knows exactly what the ninja religion is truly based on.
As far as inventing your own religion, there is a wide array of fodder available in Greek, Egyptian, Roman, and Norse mythologies. If you dig into any of these, you will find that all of them follow a central theme: the gods were created in order to explain natural occurrences. From there, various good luck rituals evolved into deeply significant religious practices.
If the timeline of your story-world goes back far enough, you can use an even more interesting technique. In order to explain this, I first need to tell you about Audie Murphy. If you’ve never heard of him, let me start by saying his was the most decorated soldier in United States history. He was also insanely badass.
Now, I won’t go into the details about how awesome this guy was, but here’s just one example: after the war he wrote a book about his experiences, a few years later a Hollywood studio decided to make a movie out of it, and have Audie play himself(he was already a well-known actor by then). He had them take out several parts of the book, because he didn’t think they would be believable in a Hollywood setting.
Now, it’s important to remember that Audie Murphy was human. He was perhaps more of a man that most of us, but he didn’t do anything that is to far beyond the strength of the human will. He was, however, awesome enough that we continue to tell stories about him nearly 70 years later.
Flash forward about 2000 years, and imagine for a second that at some point we lost every copy of Audie’s book. With each generation that the stories are retold, Audie gets a little more powerful, a little more awesome, until in about 4010 he is so outrageous that no one can possibly believe he was once a real person. So obviously he must be a god, and we should start worshiping him, right?
This is not as outlandish as it sounds, in fact it has actually happened. In Egypt’s Old Kingdom, the third-dynasty king Djoser hired an architect to build him an awesome tomb. His name was Imhotep, and he invented the iconic thing most commonly associated with Egypt: the pyramid.
Now, this is a pretty spectacular accomplishment in and of itself. We all love trend-setters, this guy set a trend that would endure for over 5,000 years(You didn’t think the Luxor got it’s shape by accident?), this is the guy who thought “Hmm, that looks cool. Let’s try it,” and impacted history in a huge way.
2,000 years later, he was deified.
True story. In the New Kingdom, over 2,000 years later, Imhotep was made the god of medicine and healing. Yeah, in addiction to inventing the defining shape of Egyptian culture, he was also a pretty good doctor, as in good enough that he treated the Pharaoh who’s tomb he would eventually build.
So this concept is not outlandish at all. In The Course Books, this technique is even used to explain one of the gods in the Rowen Pantheon.
Whatever you come up with, it needs to be fluid and believable. Religions like the Greek or Norse gods took thousands of years to evolve, and started off as stories told around campfires, or even dreams. The important thing is the way they explain some phenomenon. It doesn’t rain because the gods are angry, it rains to much for the same reason, and then you get to build a large series of rituals based on making the gods happy.