The reason that Mitzvos have this power is because they derive from a level in Elokus that is incomparably loftier than the “radiance of the Shechina,” rather, they derive from Hashem’s Will. Because mitzvos are from such a deep level in Elokus that is beyond the limitations of all worlds, from the perspective of that lofty source there in no difference between the limitation of the soul and the (relative) limitlessness of the “radiance of the Shechina” and these two things can merge.
In other words, specifically because Torah and Mitzvos are so much loftier than the Light of Hashem in Gan Eden, that is why they even have the power allow a limited creation to perceive the Elokus of Gan Eden. This is expressed in the “garments” created by the Mitzvos that the soul “wears” to enter Gan Eden and perceive Elokus there without being overwhelmed.
And this is the meaning of “Better one moment of teshuva and good deeds” – since they are rooted in Hashem’s Supernal Will – “than all the life of the World to Come in Gan Eden” – since it is only a radiance of Hashem’s Shechina, as is known.
The Tzemach Tzedek adds: Even the Infinite Light shining from Atzilus into Gan Eden is still not as great as the mitzvah itself. Since even that Light from Atzilus is only a glimmer of the truly Infinite dimension of the connection to Hashem accomplished by the mitzvah. Even though this Light of Atzilus is so much greater than the “regular” Light of Hashem invested in Gan Eden, nonetheless, it is still only a glimmer of the Essential Will of Hashem found in the Mitzvah that transcends the entire World of Atzilus.
Nevertheless, teshuva and mitzvos are called “garments,” which enable one to grasp the radiance of the Shechina. This should suffice for those who understand.
Based on all the above, we answered the question that was asked at the beginning of the maamar:
If mitzvos are better than all “the World to Come,” then why are they merely “garments” for the soul to enter Gan Eden? The answer:
There are two aspects of the mitzvos. One is the source of Mitzvos is from Hashem’s Essential Will, will transcends the limitations of all worlds, and is above and beyond the realm of Gan Eden, known as “the World to Come.” The second is how the mitzvos come down here into this world. When a Jew performs a mitzvah in this world, he not only connects to the source of the Mitzvah, Hashem’s Essential Will, but he also creates a “garment” for his soul to enable it to perceive the Elokus in Gan Eden known as “the radiance of the Shechina.”
The fact that Mitzvos also create a garment for the soul to enter Gan Eden is specifically because their source is so lofty and unlimited that it has the power to combine such opposites as a limited soul of a person and the (relatively) limitless Light of Hashem in Gan Eden.
The Alter Rebbe has described how precious mitzvos are, that they are beyond the whole category of the realm of Gan Eden, seemingly the only thing important in life should be to do mitzvos.
Now we need to understand: If mitzvos are so important, and are greater than mystical revelations of Hashem in Gan Eden, why spend time trying to awaken a love and fear for Hashem through contemplation, wouldn’t it be a better use of the time to just do more mitzvos?
The answer will be: Mitzvos are performed with physical things in this world. For these “garments” of the mitzvos to ascend to Gan Eden and serve as the spiritual interface between the soul and Elokus, they need to be “elevated” by the “wings” of the love and fear of Hashem.
