Matthew 12:35-36 says,
A good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things.How does the treasure of the heart, good or evil, get there? How does one build up good treasure in his heart? The answer, at least in part, is that he builds up treasure through his way of relating to the world. If a person relates to the world as God asks, he will build up good treasure. If he does not, then the treasure of his heart becomes evil. This way of relating to the world is exactly what habits are all about: the way we move about and interact with others, both physically and mentally. Habits of the mind can be just as powerful as habits of the body, but they are still learned behaviors that have physically shaped our brains and help us to behave in certain ways. And even habits of the mind and heart begin with the body.
This point was really brought home to me just the other day. I was standing at the kitchen sink, washing dishes and thinking about all this and praying, when my 3 year old came up behind me and startled me by grabbing my legs and making me lose my balance a little. My first reaction was not a kind, "Watch out, honey, please don't knock me over", rather it was "M, stop that right now! You can't grab onto me like that!" said in a pretty mean tone of voice. Now my mind had just right then been in beautiful places and thinking beautiful thoughts - trying to pray even, but when the interruption came I immediately lashed out and acted on my annoyance at being disturbed because that is my habitual response to annoyance. My trained habit to lash out when someone gets in my way overrode my thoughts about how habits affect us!
This incident really brought clarity to the conviction that I have that it is so important to teach children ways of relating to others that are godly. It doesn't matter if they understand right now. What matters more is that they acquire the habits of godly people so that when they are ready to understand, the Christian life is that much easier for them to pursue. Charlotte Mason put it this way:
The child who starts in life with say, twenty good habits, begins with a certain capital which he will lay out to endless profit as the years go on.Of course none of us is perfect and my children will have their struggles and imperfections just like others, but that is no reason to forgo the purposeful and careful cultivation of good habits now, while they are young, in order that they might continue in that way when they are grown.