There is a chassidisheh, avodah’dikeh [“geared to self-improvement”] interpretation of the saying: “On account of our sins we were exiled from our Land, and distanced from our Earth [in the Holy Land], and we are not able to ascend ... ”In my own words: Learning Torah and davvenen should be motivated by a desire to bring one’s inner self close to Hashem, and ultimately to unite it with Him. Of course, every Jew should feel this way, but a self-identifying chossid is all the more responsible to feel this way.
The Hebrew word for sin, chait, can also mean chisaron, a shortcoming.
The word for land, eretz, is etymologically related to the word ratzon, desire, as it is written in Medrash: “Why is [the Land] called eretz? Because ratzesa, it wants, to perform the will of its Maker.”
Adamah, which means earth, [is related to the word adam, man]. Man is called adam because Hashem created the human body from the earth.
This, then, is the deeper meaning of this saying:
“On account of our faults”: This refers to the fault of not engaging in the avodah of Chassidus in a way of pnimiyus [“innerness”]; rather, we relieve our duty with a superficial level of service [“chitzoniyus”], by reading through a chapter of Tanya just as one reads through a chapter of Tehillim, and “the service of the heart” is unheard of. On account of all such shortcomings ...
“We were exiled from our Land”: We have gone astray, may G–d save us, and we have completely forgotten the flavor of a true desire [for G–dliness]. [This leads to ... ]
“We have been distanced from our earth”: As the days pass, we become distanced further and further from our adam, i.e., from our chassidishe inner self, which is immersed in inner change [“avodah pnimis”]. This may reach the point at which ...
“We are not able to ascend”: We are, G–d forbid, no longer able to rise. We have neglected ourselves to such an extent that we can no longer lift ourselves back up.
 From the Mussaf liturgy for the festivals.
 As in the verse, “I and my son Shlomo were counted offenders”—I Melachim 1:21.
 Bereshis Rabbah 5:7.
 Cf. Bereshis 2:7.
 “Avodas haTefillah”—Sifri, Devarim 11:13.
Likkutei Dibburim, Vol. 2, p. 541.
However, in order to attain and maintain this desire, never mind to actually reach this goal, intense and consistent effort is required. For it is human nature that once one gets into the habit of doing something—anything, even the most precious and rare of activities—one becomes accustomed to doing it, takes it for granted, and does it automatically and robotically.
Likewise, even such sublime privileges as studying Hashem’s supernal wisdom, standing in a private audience with Him in prayer, and bonding with Him by performing His commandments, can become a tiresome chore that one discharges mindlessly.
However, every Jew has been granted the tools with which to counteract this natural tendency, and in our generation, the avodah of Chassidus. This is the idea of striving for inner change through various means, particularly through study of Chassidus followed by avodas haTefillah (see here), attending farbrengens, and so on. When we take the time to do these things, we actively prepare ourselves for the Mitzvos that we perform by infusing this performance with meaning and purpose. We then perform them with fresh enthusiasm, and even though we donned the same Tefillin yesterday, come today we are excited and inspired about donning them again.
The mind and heart is then immersed in the Mitzvah that one is performing. For example, one recites the beracha on the Tefillin carefully, fully aware that one is speaking to Hashem and that He is listening, and that one is now performing a Mitzvah of Hashem. He focuses on the precise meaning of each word of the beracha, and as he dons the Tefillin, he reflects upon their deeper significance and practical relevance, and of the difference between the symbolism of the head and the hand Tefillin, and so on. And so he does with all the Mitzvos.
Every Jew who has committed himself to be a Chabad chossid knows that as a chossid, he should be striving to improve and ultimately transform his inner self, his intellect and emotions, through rigorous devotion to learning Chassidus and avodas hatefillah. Thus, even if he neglects to do so, deep down, he wants to devote himself to inner change.
He may (and should!) have embarked upon his inner journey as a chossid inspired and idealistic, with ambitious goals for self-transformation, and confident of success. But over the course of time and the repetition of the same sort of thing, and often due to various personal, financial, and social pressures, the once-aspiring chossid may well lose the motivation to push himself to focus, to prepare, and to rev himself up to serve Hashem with genuine feeling through learning Chassidus at length, engaging in hisbonenus, and so on.
And with each time that he learns without reminding himself that he is studying Hashem’s holy Torah, or barely concentrating altogether, or with every time that he davvens without thinking and feeling that he is standing before Hashem in a private audience, and without concentrating on the meaning of the words, he becomes coarsened and corrupted. His animalistic side becomes more and more dominant, and he enters a downward spiral.
The less he exerts effort, the more his motivation to do so seeps away. Once caught in this vicious cycle, he deteriorates further and further until he enters a state of almost total desensitization, apathy, and perhaps even antagonism to all things spiritual. He may remain technically observant, but his observance is nothing but an empty shell. He languishes in this weakened state until he reaches a point at which even when he regrets his neglect and tries to crawl out of his lowly state, he feels that doing so is unattainable. He has reached a nadir at which only an intense spiritual energy from Above, and in particular, the prayers and intercession of the Rebbe, can pull him out of his spiritual coma.
In summary, neglecting avodah leads one to spiritual degeneration. Let us devote ourselves to avodah, thereby not only preventing any such pitfalls, but fixing “our faults” and returning to “our desire” and “our adam”—the Jew’s true inner self.