The first Mishnah in Pirkei Avot states: “Moshe received the Torah at Sinai and transferred it to Yehoshua. Yehoshua then transferred it to the Elders and the Elders transferred it to the Prophets. The Prophets transferred it to the members of the Great Assembly. They (the members of the Great Assembly) said three things: Be patient in judgment, establish many students, and make a fence for the Torah.”
Avot of Rabbi Natan states that Bet Shammai say that one should only teach a student who is wise, humble, and a Ben Torah. Bet Hillel, on the other hand, say that one should teach any student, for there were many criminals among the Jewish nation who came closer to Torah learning and as a result, merited having righteous offspring.
The opinion of Bet Shammai is seemingly quite understandable, for if one teaches a student who is not humble, when he grows somewhat in Torah study, he will immediately view himself as a wise man which will cause him to disagree with the Torah luminaries of the generation and this will cause great destruction. Similarly, if one teaches a student who is not intelligent, even after several years of learning, the student will still expound the Torah in an erroneous and crooked manner which will likewise cause great destruction. History has already shown several unworthy students who had studied a small amount of Torah and then proceeded to sway the Jewish nation from the proper path. However, according to Bet Hillel, this risk is worthwhile, for the light of Torah may bring back many straying Jews to the fold and they will then produce good and pious Jews.
Although the Halacha follows the opinion of Bet Hillel, this does not mean that one should teach Torah to literally every single person, for the Gemara (Chullin 133a) states, “One who teaches an unworthy student shall fall into Gehinnom.” Maran zt”l explains this to mean when one is clearly aware that this student is going in an unsavory path; however, if one is not aware of the student’s actions or behavior, it is a Mitzvah to teach Torah to such a student.
Nevertheless, Maran Rabbeinu Ovadia Yosef zt”l writes that nowadays, it is a Mitzvah to teach Torah even to students who are unworthy as long as they appear to be products of “captured children,” i.e. that they do not observe Torah and Mitzvot as a result of their distorted secular education. It is likewise a Mitzvah to bring inmates in prison who were charged with heinous crimes to Torah and Mitzvot, for many of them return to the correct path after being taught Mussar and being rehabilitated. Indeed, Maran zt”l once instructed us to teach Torah to a wayward youth who used to be a Ben Torah but unfortunately strayed from the path of Torah, for only the Torah has the power to return him to the proper path. (However, one may not teach a student who only studies Torah in order to destroy.)
One must likewise try to spread Torah and Mitzvot lovingly to one’s relatives. One should not lecture them endlessly; rather, one should speak to them in a pleasant manner so that they may accept even one good resolution upon themselves, for this one thing will bring them further and further in their Torah observance. By registering friends to receive the daily “Halacha Yomit” email (obviously with prior consent), one merits teaching them Torah every day; the light of the Torah will surely raise their spiritual level. We have indeed seen some fruits of our labor and today, thank G-d, there are over twenty-five thousand regular members who have registered to receive these Halachot every day. Countless others receive these Halachot by other means and ascend the levels of Torah and Mitzvot and become truly knowledgeable in Torah, how fortunate they truly are.