Anyone who has learned Torah can teach those who know less.
Torah is taught by Rabbis and knowledgeable Jewish laity. See also:
The Torah teaches, instructs, commands, exhorts, advises, reveals, inspires...
The Talmud.
Jewish answer:By learning and fulfilling the Torah.
The Torah teaches Jews to love and revere God.
The Torah teaches us that they were the first commandments given to the People from God.
How to live. The Torah is vast; covering belief, observance, history and information. See the attached Related Links for some info.
Genesis teaches us about world origins, how the nations came to be, and the early generations of the Israelites and their forbears. From people such as Abraham and his family, we learn many forms of righteousness.
The Torah teaches us about God so that we know something about Whom we're worshiping. It describes His ways, what He wants us to do, etc. It also contains several examples of prayer.
The Torah teaches that sins are punished, whether in this world, the next world or both. The way to avoid that is through Teshuvah (returning to God and the Torah and keeping the mitzvos [commands]).
The Torah calls itself by that name (Deuteronomy ch.31). The word Torah means 'teachings'. The name is significance because the Torah teaches Jews how to live righteously. The complete Jewish Bible is called the Tanach. The word Tanach is an acronym made from the names of its three sections: Torah (Teachings), Nevi'im (Prophets), K'tuvim (Writings).
Jewish tradition teaches that the prophets were great Torah-scholars and thinkers, who studied under the elder prophets of their generation.
The major focus of belief in Judaism is the Torah, since it teaches us about God and His laws, as well as our origins and history.