There are as many kinds of stories out there as there are crayons in a box.

What’s your genre? The key question to help you discover this is usually: what kinds of stories do you most like to read? I say usually, because I love reading and listening to mysteries, but I haven’t figured out how to write a good one…yet. I also love reading historical fiction, and the more I read, the more I learn about how it’s done.
Based on your favourite genres of fiction, which would you most like to write? Why? I like Historical Fiction because it reminds me that every historical figure that inspires me to write about them has actually lived and died, loved and hated, succeeded and failed. Each is real and unique and deserves to be known and understood, at least to some degree. When I create characters in historical fiction, it is with the hope that they will become as real as if they had actually lived.
Perhaps you wish to write Children’s Fiction because you love to tell stories to the little people in your life. Maybe you want to try writing for teens in order to help them better understand themselves and their parents and life in general. The draw to Fantasy may be the opportunity to create a new world with its own set of rules and parameters. Of course, there’s always help on the web. Here’s just one site of many to check out: http://fictionwriting.about.com/od/genrefiction/a/How-To-Choose-A-Genre-For-Your-Novels.htm
Although most of us know what kind of story we want to write, the conundrum that presents itself is whether to write what’s on our hearts or what will sell best. The answer depends on our goals. If our number one objective is to sell our story, then we must research and write what’s selling. My agent once suggested that anything with a buggy and bonnet on the cover would sell. (I can’t tell you why, after all this time, but that’s another issue.) We can still be creative when we write for the market, but we must make sure we’re okay with it.
Personally, I need to write from the heart, whether it sells immediately or not. Pair that with the premise of Kevin Costner’s movie, Field of Dreams: “Build it and he will come.” Write it, and the readers will come, so we hope and pray. The choice is up to us as individuals.
For the Christian writer, published or not, the choice of genre is important. If we plan to build a platform (the genre and style of writing that people think of when they recognize our names, also referred to as our brand), we will need to concentrate on writing in one genre until we are known by our readers.