"Let the little children come to me, and do not hinder them, for the kingdom of God belongs to such as these. I tell you the truth, anyone who will not receive the kingdom of God like a little child will never enter it." (Mark 10:14-15)
If you've studied the Bible or attended church for long enough, you've probably heard or read countless teachings on this. So I may not have anything new to add. I will, however, give you my thoughts.
Children are probably the most rule-aware subset of humans. You may not believe this, but they are. They are rule-aware because children are still trying to figure out the world around them, so they do their best to catalog everything they see and hear. Thus people are generally only "good" or "bad," because they do not have the mental subtleties to see the gray area.
This is quite clear in language. Children who grow up speaking English are stuck with attempting to figure out a language which is based on both the Romance and Germanic tongues, each with their own rationale. So it helps to know things like "I before E, except after C." But there are soooo many intricacies of the language which you and I take for granted now, because we've memorized it. But you will see a child attempting to follow the rules, and getting it all wrong, until they learn. (House-Houses verses Mouse-Mice, for example).
All that to say that when a child "learns right from wrong," they do not question it. Of course, a child's favorite question is often "why?" (typically because they like to have the rationale behind the rules they're learning), but you can often tell a child "Because that's what God teaches us" and they'll be content.
So if you take the time to teach your children God's commands, they will not only learn them, but they will parrot them back to you. Don't even think about lying in front of a child who has just learned that lying is wrong!
Many people read the above verse and talk about how we must be innocent as a child to get to heaven. This is true. But we must also be dilligent to learn God's laws and apply them to our own lives. And, really, children do this better than most any other age group. So you want to inherit in the Kingdom of God? Be like a child. Learn what is right and wrong, and stick to it.