How [does one fulfill] the mitzvah of dwelling in the sukkah? One should eat, drink, and live in the sukkah, both day and night, as one lives in one’s house on the other days of the year: for seven days a person should make his home his temporary dwelling, and his sukkah his permanent dwelling
Shulchan Aruch, Orach Chaim 639:1
G-d says… “I have one easy mitzvah, and sukkah is its name”
Talmud, Avodah Zarah 3a
“In sukkot you shall dwell for seven days,” instructs the Torah, “…in order that your generations shall know that I made the children of Israel dwell in sukkot when I took them out of the land of Egypt.” 
Our sages, noting the Torah’s use of the verb “to dwell” in the above verses, define the mitzvah of sukkah as a commandment that, for the duration of the festival of Sukkot (Tishrei 15 to 21), the sukkah is to become our primary dwelling place. Everything ordinarily done in the home should be done in the sukkah.
So every autumn, just as the weather is turning inhospitable, we move outdoors. For a full week, we exchange our regular home for a home which leaves us at the mercy of the elements, demonstrating our trust in G-d’s providence and protection, as our ancestors did when “following Me in the wilderness, in an uncultivated land.”
Dwelling in the sukkah for seven days is a beautiful and inspiring experience; however, one would hardly describe it as “easy.” Yet this is the mitzvah singled out by the Talmud as G-d’s “easy mitzvah”!
The Commanding Connection
“Mitzvah,” the Torah’s word for the divine precepts which guide and govern our lives, has a dual meaning: the word means both “commandment” and “connection.”
In commanding us the mitzvot, G-d created the means through which we may establish a connection with Him. The hand that distributes charity, the mind that ponders the wisdom of Torah, the heart that soars in prayer, even the stomach that digests the matzah eaten on the first night of Passover—all become instruments of the divine will. There are mitzvot for each limb, organ and faculty of man, and mitzvot governing every area of life, so that no part of us remains uninvolved in our relationship with the Creator.
Therein lies the uniqueness of the mitzvah of sukkah. While other mitzvot each address a certain aspect of our persona, the mitzvah of sukkah provides a medium by which the totality of man is engaged in the fulfillment of G-d’s will. All of the person enters into and lives in the sukkah. “Sukkah is the only mitzvah into which a person enters with his muddy boots,” goes the Chassidic saying. For the seven days of Sukkot, the sukkah is our home—the environment for our every endeavor and activity.
Man and Turf
The specialty of the sukkah as an all-embracing medium of connection with G-d is best understood in light of the significance of the “home” to the human being.
Our sages point out how deeply rooted is man’s desire for a home. The desire for a home is much more than the need for shelter and security—the satisfaction of these needs alone, without a plot of land to call one’s own, does not satisfy the craving for a home. The Talmud goes so far as to say that:
“One who does not possess a homestead is not a man.” 
The need for a home is intrinsic to the soul of man and a defining aspect of the human state.
Thus, a person’s identification with his home is not confined to the hours he spends within its walls. Also when he is at work, visiting with friends or taking a stroll in the park, it is as the owner of this particular home that he works, visits or strolls. Since his very humanity is incomplete without it, it is part and parcel of everything he does.
For the seven days that we make the sukkah our home, it comes to form an integral part of our identity. Everything we do, including what we do outside of the sukkah, is included in the “connection” with G-d achieved by this mitzvah.
Easy as Life
Now we might understand why the mitzvah of sukkah is G-d’s “easy” mitzvah.
A person can approach the fulfillment of G-d’s commandments in one of two ways: as a duty, or as the purpose of his existence.
The “dutiful” observer of the mitzvot sees the purpose of his life in the realization of his own personal ambitions. At the same time, he recognizes that G-d is the master of the universe and is the one who created him, granted him life, and continues to sustain him in every moment of his existence. So he feels duty-bound to obey G-d’s commandments.
But then there is the person who understands that:
“I was not created, but to serve my Creator.” 
He recognizes this as his true “I” and as the ultimate fulfillment and realization of who and what he is.
If one assumes the first approach, regarding the observance of a mitzvah as a duty, there will be both “difficult” and “easy” mitzvot. One might fulfill them all, perhaps even willingly and joyfully, but some will be more pleasant and inspiring, others more tedious and toilsome. The expenditure of time, effort or money that a mitzvah requires will also affect the degree of difficulty one experiences in its fulfillment.
But when we see the fulfillment of the divine will as the very stuff of our life, the concept of a difficult mitzvah is nonexistent. All mitzvot are “easy,” for they do not constitute an imposition on our life—they are our life. Indeed, there will be no division between the mitzvah and “non-mitzvah” areas of our life. When we live to implement G-d’s purpose in creation, our entire life—including those activities which are not explicit mitzvah acts—becomes a single, seamless quest to connect to our Creator and serve His will.
All mitzvot can be observed in either of the above ways; but there is one mitzvah whose terms of observance call for nothing less than the second approach. The mitzvah of sukkah does not tell us to do something; it tells us to be something—a sukkah-dweller. The way to observe this mitzvah is to make the sukkah our home—our environment, our roots, our very identity—for seven days of each year of our life.
And when we apply the model of the mitzvah of sukkah to our observance of all of G-d’s commandments, they, too, assume the all-embracing quality of the sukkah. They, too, become as “easy” as life.
Based on an address by the Rebbe, Sukkot 5716 (1955)
Adapted from the teachings of the Rebbe by Yanki Tauber
. Leviticus 23:42-43.
. Talmud, Sukkah 28b; Mishneh Torah, Laws of Sukkah 6:5; Shulchan Aruch, Orach Chaim 639:1. This also defines when a person is not obligated to do something in the sukkah: one is not obligated to eat or sleep in the sukkah when, under similar conditions, one would not do so in one’s own home (Talmud, ibid.; Shulchan Aruch, ibid., subsections 2 and 5).
. Jeremiah 2:2.
. Talmud, Yevamot 63a, as per Tosafot, ibid., s.v. she’ein lecha.
. Talmud, Kiddushin 82b.
. This is also why the festival of Sukkot derives its name from the mitzvah of sukkah, and not from its other mitzvot (e.g., the taking of the “Four Kinds”).
. Likkutei Sichot, vol. II, pp. 417-418.