Writing isn't about messages. People who sit down at their computers or typewriters or notebooks to force feed a message to their readers are doing it wrong. Books can have messages. They can be about important things. But the message isn't the IT. The plot, the characters, the story of it all, that's the IT, the thing about which you could be concerned.
But you should still have something to say. Don't worry if it's worth saying; it'll be worth it to someone, somewhere. You should have a point of view that's unique to you.
Hannah Moskowitz is a good example of someone with something to say. So far I've only read BREAK, but based on what I've read about her forthcoming books INVINCIBLE SUMMER and ZOMBIE TAG, along with BREAK, it's pretty clear to me that Hannah has something to say about the nature of brotherhood. About the interactions between members of a family. About how your family can ruin you but how you'll try to support them anyway. Her characters in BREAK were so frustrating because I could see that their fierce love and loyalty for one another was killing them. I've heard that in INVINCIBLE SUMMER, the brotherly relationship goes beyond co-dependent, beyond affection to something more. I can't wait to read it because Hannah has something interesting to say about brothers and family and how fucked up they all can be.
But I guarantee that she didn't sit down to cram that down your throat. She wrote a good book and her point of view simply bled through.
I have something to say about how regular people relate to a screwed up world. I don't care about extraordinary people. They're boring to me. I think ordinary people, quiet overlooked people are the real heroes. But I don't set out to make you see that. When I sit down to write, I want to tell you a story about a kid who's got one day to live, about a group of friends partying in parallel worlds, about a guy playing hide & seek from Death in the hospital where his parents died.
So make sure you have something to say, just don't worry so much about saying it. Write a great story and the rest will follow.