You have theme and you have some characters. In writing a novel, you're going to have put forth some good storytelling as well, and plot complexity doesn't always run a parallel to that good storytelling. Sometimes the simplest of tales can carry the deepest themes, so don't rely on an automatic association between story complexity and deep meaning.
Also, too much narration in a story with such a heavy emphasis on such a theme could produce a didactic nosedive into philosophy if the author isn't careful about how narration is being used. Showing the essence of humanity is kind of like defining life (we can list properties of living things that are not characteristic of non-living things, but to come up with a good definition of life is difficult, even [particularly] for biologists). On a less grand scale, highlighting aspects of human nature is what novelists do all of the time. It's called characterization. I agree with SF--read, and look for novels that have the kind of heavy theme you want to portray. But please remember that writing for publication means writing for the reader. He/she will want a damn good story.
I think you've set a good challenge for yourself, and sturdy challenges can have big payoffs. I'm rooting for that here. I will be very interested in how this comes out. Please keep us informed and keep asking questions.
And welcome to AW.