How to write about a universal truth
Many of my clients (and authors in general) write because they want to express a universal truth. Or because they want to encourage readers to accept an emotional or social concept, like self-love or the benefits of helping others. It can be tempting to state simply and absolutely: “Treat others as you want to be treated,”or “You will be happy if you just love yourself as you are.” And then just leave it at that. I advise against it, though. For one thing, that’s not very much fun, as reading experiences go. And it’s also not convincing.
When was the last time you heard a motivational speaker, or anyone, tell you how to act to make your life better and you immediately and fully accepted that advice? Likely never. You waited to hear examples of that advice working for other people. Not to mention you probably needed a bit of explanation about how one goes about implementing their pithy advice. Same goes for kids and their parents.
Your story—about a character acting out the advice or the universal truth you want to share with readers—can help children see what you mean when you say, for example, that Nevy learned to treat others as she wants to be treated. That’s not always an easy thing to do, so the specific actions she takes to reach that point are instructive, not to mention a lot of fun to read.
Be specific
To help readers learn, accept, and agree with your universal truth, or "moral of the story," your story needs to be a specific and explicitly described example of that truth playing out in a character’s life. It’s easy to understand the universal truth when we see how it works in “reality.” (The reality of the fictional world, in this case.) It can be harder to understand, to trust the truth of, and to believe a concept if it is told to us in generic terms.
So instead of simply telling children to “treat others as you would like to be treated,” tell them a story where a character treats others badly and is treated badly in return, and therefore winds up having a bad day; but later the character treats others kindly and is treated well in return, and this leads to having a great day. After seeing this example situation play out, kids are likely to understand what it means to “treat others as you want to be treated” and why it’s important. That real example shows them what the idiom means.
How Nevy learns a lesson
It’s more than “Nevy was mean to her classmates on the bus, so they were mean to her at recess.” What is “mean”? What did Nevy do? What did the other kids do at recess? And why do I, the reader, care?
Maybe Nevy threw her banana peel at Bobster and Lolly, who were sitting in the seat in front of her.* And maybe Bobster and Lolly ignored Nevy at recess.*
These are real actions that readers can visualize. Kids can imagine how these actions might make them feel, or how they might feel doing the actions. It is the specifics that help readers connect with their emotions and therefore the characters’ emotions—and finally, the characters. This helps them understand and believe the universal truth, the moral if you like, of your story. And if you do it well, you never have to state that boring old idiom at all!
There's more to the story
What we’ve done by offering specifics here is show kids how to make other people be mean to us. To reveal the second half of that truth, what specific actions might Nevy do that encourage Bobster and Lolly to be nice to her tomorrow? When you get these specific actions (scenes) down on paper, you will help young readers understand what it means to "treat others like you want to be treated"; why it’s important to do so—Nevy feels better, obvi; and how to do it.
Being specific is just part of what will convince readers to stick with your story. Even providing specific actions won't make your book an exciting read. It is a start, though. Other elements to consider include plotting, characterization*, voice, and other big picture issues. I will offer notes on these topics soon.
*But why did Nevy throw a banana peel? And what’s wrong with not hanging out with B and L for one recess? The answers to these questions are also important and need to be answered in your story. They are about characters' goals and motivations and are key to a well-told and fun story.