Setting An Example
In the education of children, it is meaningless to say simply, "This is permitted; that is forbidden." A child must see his parents perform the mitzvos joyfully. If a child hears his father say, "It is very difficult to keep Shabbos and Yom Tov, but I, nevertheless managed to overcome the temptation to work on Shabbos," the son will not necessarily follow suit. He may rationalize "I am not as strong willed as my father; I cannot withstand the temptation." But if children hear from their parents that it is not at all difficult to keep the Torah, and that mitzvos are wonderful for they are the essence of life and the length of our days, their education has a chance of being effective.
(Rabbi Moshe Feinstein)