"It takes all kinds." That, essentially is the message of the mitzvah of the "Four Kinds" -- the etrog (citron), lulav (palm frond), hadas (myrtle) and aravah (willow) -- over which we recite a blessing on the festival of Sukkot. In the words of the Midrash:
The etrog has both a taste and an aroma; so, too, do the people of Israel include individuals who have both Torah learning and good deeds.... The date (the fruit of the lulav) has a taste but does not have an aroma; so, too, do the people of Israel include individuals who have Torah but do not have good deeds.... The hadas has an aroma but not a taste; so, too, do the people of Israel include individuals who have good deeds but do not have Torah.... The aravah has no taste and no aroma; so, too, do the people of Israel include individuals who do not have Torah and do not have good deeds.... Says G‑d: "Let them all bond together in one bundle and atone for each other."
The Lubavitcher Rebbe points out that the Midrash is not just saying that "all are part of the Jewish people" or "all are precious in the eyes of G‑d" or even that "all are necessary"; it says that they "all atone for each other." This implies that each of the Four Kinds possesses something that the other three do not, and thus "atones" and compensates for that quality's absence in the other three.
In other words, it's not just that it takes all kinds to make a people -- it also takes all kinds to make a person. And Sukkot is the time when we bond with each other so that the other's qualities should rub off on ourselves.
The etrog says: "I am perfect. I balance learning and doing in flawless equilibrium. In my life, knowledge and action do not overwhelm or displace one the other, but rather fulfill and complement each other." This is something we all need to say, at least once in a while. We all need to know that we possess the potential for such harmonious perfection, and that we each have those moments in our lives when we attain it.
The lulav says: "I am utterly devoted to the pursuit of wisdom, awareness and self-knowledge. Doing is also important, but my first priority is to know G‑d and (thereby) my truest self, even if this means withdrawing from involvement with the world." This is something we all need to say, at least once in a while. We all need to know that there is the potential for such consummate knowledge in us, and that we each have those moments in our lives when we attain it.
The hadas says: "What our world needs is action. Knowledge of G‑d and self-awareness are worthy goals, but I have a job to do. I need to build a better world -- enlightenment may have to wait." This is something we all need to say, at least once in a while. We all need to know that our mission in life is to "make the physical world a home for G‑d", and that there are times when the need for action takes precedence over everything else.
The aravah says: "I have nothing. I am nothing." This is something we all need to say, at least once in a while.