Here are two very different approaches to moral education:
The outward-in approach. Inform the child what the rules are. Do not expect the child to like the rules or regard them as wise. Instead, enforce compliance through punishment and reward. Secondarily, explain the rules, with the hope that eventually the child will come to appreciate their wisdom, internalize them, and be willing to abide by them without threat of punishment.
The inward-out approach. When the child does something wrong, help the child see for herself what makes it wrong. Invite the child to reflect on what constitutes a good system of rules and what are good and bad ways to treat people, and collaborate in developing guidelines and ideals that make sense to the child. Trust that even young children can come to see the wisdom of moral guidelines and ideals. Punish only as a fallback when more collaborative approaches fail.
Though there need be no neat mapping, I conjecture that preference for the outward-in approach correlates with what we ordinarily regard as political conservativism and preference for the inward-out approach with what we ordinarily regard as political liberalism. The crucial difference between the two approaches is this: The outward-in approach trusts children's judgment less. On the outward-in approach, children should be taught to defer to established rules, even if those rules don't make sense to them. This resembles Burkean political conservativism among adults, which prioritizes respect for the functioning of our historically established traditions and institutions, mistrusting our current judgments about how to those institutions might be improved or replaced.
In contrast, the liberal ideal in moral education depends on the thought that most or all people -- including most or all children -- have something like an inner moral compass, which can be relied on as at least a partial, imperfect guide toward what's morally good. If you take four-year-old Pooja aside after she has punched Lauren (names randomly chosen) and patiently ask her to explain herself and to think about the ethics of punching, you will get something sensible in reply. For the liberal ideal to work, it must be true that Pooja can be brought to understand the importance of treating others kindly and fairly. It must be true that after reflection, she will usually find that she wants to be kind and fair to others, even without outer reward.
This is a lot to expect from children. And yet I do think that most children, when approached patiently, can find their moral compass. In my experience watching parents and educators, it strikes me that when they are at their best -- not overloaded with stress or too many students -- they can successfully use the inward-out approach. Empirical psychology also suggests that the (imperfect, undeveloped) seeds of morality are present early in development and shared among primates.
It is I think foundational to the liberal conception of the human condition -- "liberal" in rejecting the top-down imposition of values and celebrating instead people's discovery of their own values -- that when they are given a chance to reflect, in conditions of peace, with broad access to relevant information, people will tend to find themselves revolted by evil and attracted to good. Hatred and evil wither under thoughtful critical examination. So we liberals must believe. Despite complexities, bumps, regressions, and contrary forces, reflection and broad exposure to facts and arguments will bend us toward freedom, egalitarianism, and respect.
If this is so, here's something you can always do: Invite people to think alongside you. Share the knowledge you have. If there is light and insight in your thinking, people will slowly walk toward it.
Related essay: Human Nature and Moral Education in Mencius, Xunzi, Hobbes, and Rousseau (History of Philosophy Quarterly, 2007)