In addition to a system of judges and sheriffs, Moses instructed the Jewish people to appoint a king over them.
The Personal King
שׂוֹם תָּשִׂים עָלֶיךָ מֶלֶךְ אֲשֶׁר יִבְחַר ה' אֱלֹקֶיךָ בּוֹ וגו': (דברים יז:טו)
[Moses told the Jewish people,] “You may indeed appoint a king over yourself, whom G‑d chooses.” Deuteronomy 17:15

Although the Jewish people have not had a king since the destruction of the first Temple and will not have another until the Messiah himself, we are still enjoined to appoint a higher authority over ourselves, both individually and collectively, wherever relevant. The sages therefore say to each one of us: “Provide yourself with a teacher [of Torah],” with whom we should consult on all matters of spiritual life.

We should not delude ourselves into thinking that we can rely on our own “judges and sheriffs.” Nor should we think that there is no one capable of understanding us sufficiently to serve as our “king.” The Torah assures us that if we search properly and diligently, we will indeed find the mentors best suited to our spiritual needs.1