As a writer, it's hard not to imprint your own beliefs onto your writing, especially if it's an agenda or political leaning you're passionate about. In fact, it's pert-near impossible. But if I'm reading along and begin to feel that you're manipulating me into believing what you believe,
there's a good chance I'll quit reading. I might let you lead me, but I won't let you strong-arm me.
One way to get your point across without losing your reader is to let your characters represent your beliefs. Instead of you, the writer, describing something as "evil" or "stupid," you have your characters do it. For me to agree with them, though, I would need more than just them
using those adjectives. I would want to understand their reasoning, see what they see. I may not agree with their viewpoints, but I can understand why they believe the way they do.