The anniversary of the passing of the first Chabad Rebbe, Rabbi Schneur Zalman of Liadi, known as the Alter Rebbe, author of the Tanya and the Shulchan Aruch, is celebrated on the 24th of Tevet. The Alter Rebbe used to say that in the world to come, "the soul will be nourished from the body." There will be a reversal of nature: the essential (the soul) will become incidental while what was once incidental (the body) will become essential. This is the real secret of "Joseph is still alive": the od of Joseph (which is in each Jew) will live eternally, while the soul (the aspect of "I will praise G-d while I live") will receive its principal vitality from the body which will live forever. [Rav Yitzchak Ginsburg - http://www.inner.org/times/tevet/tevet59.htm]
Has anyone seen the source for this teaching of the body nourishing the soul in the world to come? I know the Tanya discusses the 248 limbs being clothed in the 250 columns of light from Keter, and he mentions the mitzwoth (these same 250 columns of light) as the clothing of the soul in Gan Eden, but he also says there that davka the Torah we learn is the food of the Neshamah in Gan Eden. (all that can be found in iggrot kodesh - second to last section of tanya)
From the title of the post we can learn another teaching, since we're here, we might as well learn somehting right?
Rebbe Nachman teaches (and we've mentioned it in the past) that "The land that eats her inhabitants" teaches a very deep lesson: That when we live in Israel, it consumes us and makes us into part of herself, just as the body consumes food and turns it into (flesh/bone/blood/etc) part of the body. In the same sense we can say that when we live for the sake of our soul, our body is consumed by and turned into part of the soul.
This can be substantiated by the teaching in Tikkunei Zohar that the angel in charge of the days of the week, (His 'nickname' is Mat -- we don't pronounce the names of angels with the exception of the four main ones Michael, Gavriel, Refael, and Uriel) is the body of Chanoch, which he turned into a holy angel through his divine service.