What are we trying to do as writers of story, especially long-form story? I recently read an interview Joyce Cary gave to The Paris Review in 1954*. Here is a bit of what he said in that interview.

“I don’t care for philosophers in books. They are always bores. A novel should be an experience and convey an emotional truth rather than arguments.”

This is the entire point of fiction. As soon as a story begins to tell the reader what they should think – beyond expecting them to accept the story that is being told – the story becomes a treatise.
Of course we must allow characters to speak and even say things that demand us to consider our beliefs. But the craft concern is for the writer not to step onto the page. We must never sense that we are reading the author’s perspective or thoughts. Characters will say things, but we shouldn’t feel, as readers, that we are being expected to accept such things as statements of argument for a cause.

Our goal as writers of fiction is not intellectual truth. Our goal is to write emotional truth. We are not seeking agreement with our reader, we are seeking something else. We are seeking alignment. We are seeking a mutual recognition of the truth that is driven out of the human experience – good, bad, or somewhere in-between. Let the philosophers, lobbyists, and activists do their work and let’s do ours.
Let’s tell stories that throw light on the condition of the human heart.

* http://www.theparisreview.org/interviews/5071/the-art-of-fiction-no-7-joyce-cary