This week's Parsha begins with the Pasuk of ואלה תולדות יצחק בן אברהם, אברהם הוליד את יצחק, "and these are the generations of Isaac son of Avraham, Avraham gave birth to Isaac." Rashi comments on this Pasuk that the phrase תולדות יצחק refers to Yaakov and Eisav, who are both mentioned in the Parsha. Rav Moshe Feinstein in his Darash Moshe wonders what point Rashi is making by giving us this information, and he explains that the conclusion of the Pasuk, אברהם הוליד את יצחק will help us answer our question. Prior to describing the children of Yitzchak, the Torah states that Avraham gave birth to Yitzchak. This tells us that Avraham successfully raised Yitzchak to follow in his ways. Just like his father Avraham, Yitzchak also taught the people to recognize Hashem (see רמבם הלכות עבודת כוכבים א:ג). Surely he also taught his own sons as his father taught him. Nevertheless, in spite of Yitzchak's spreading the word of Hashem in the world, and for all his efforts to teach his children the way of Hashem, one of them turned out to be the wicked Eisav.
From this we see the importance of giving our children a proper education. If all of the accomplishments of Yitzchak didn't prevent him from producing an Eisav, then we certainly must devote all of our efforts to guiding our families on the correct path and not merely set an example for them in the hope that they will emulate us. It is this need for proper education that Rashi meant to teach us with his comment that the generations of Yitzchak were Yaakov and Eisav.
The Gemara in Masechet Nedarim (פא.) elaborates on this point when it asks ומפני מה אין מצויין תלמידי חכמים לצאת תלמידי חכמים מבניהן, "Why isn't it found that because the father is a scholar his children will be scholars, too?" The Ran comments on this question שעל הרוב אינם בני תורה "usually the children are not found to be בני תורה." The Gemarah offers five different approaches to solve this dilemma. We see from this Gemarah how important the parent-child interaction is in the education of a child, as most of the time we find that there are no guarantees in life, and just because you are affected by Hashem and his word, does not necessarily mean that your children will follow in your footsteps.
In fact, Rabbi Aharon Lichtenstein relates that Rabbi Joseph B. Soloveitchik exhorted him כי ביצחק יקרא לך זרע. Rabbi Soloveitchik explained that Hashem told Avraham that the tens of thousands of his followers (see aforementioned Rambam) had to be secondary in importance to his son Yitzchak. Only by investing one's main efforts into raising his family will he be a successful parent.
חז"ל teach us on the Pasuk of ושננתם לבניכם, and you shall teach them (the words of Torah) to your children, that על תקרי לבניכם אלא לתלמדיכם do not read the word as to your children rather to your students. Rav Ruderman זצ"ל, the Rosh Yeshiva of Yeshivat Ner Yisroel in Baltimore, asks if the Torah is referring to students then why did it write children? He answered brilliantly that if a Rabbi wants to be successful he must treat each student as if he were his own child.
May we learn this lesson well and put in all of our efforts so we can be both better parents and educators and the future generations can follow in our footsteps and our traditions will be able to be passed on.