In this week's Torah portion, Nasso,

In this week's Torah portion, Nasso, we find the command to count the Levites - the sons of Gershon and the sons of Merari. The actual count of these people was taken only once, during the second year of their 40-year wanderings. What are we to learn from the Torah's inclusion of this commandment?Why did the Jewish people had to wander for 40 years in the wilderness? When the spies gave a negative report about the land of Israel, the Jewish people were reluctant to enter the land G-d had promised them. G-d, therefore, punished the Jews with 40-years of wandering and decreed that those who had been unwilling to enter Israel would not be allowed to do so. But why did G-d choose a wilderness for their wandering, as opposed to another location?
A wilderness is uninhabited by man, and indeed, the desert the Jewish People wandered through is described as "a great and terrible wilderness: snakes, poisonous serpents and scorpions, and thirst without water to quench." The Children of Israel, through their travels, were charged with transforming that wilderness and purifying the negative forces that still had their hold on the Jewish People. The cloud that preceded them as they traveled destroyed the snakes, serpents and beasts, which threatened their existence. By overcoming the obstacles in the desert the Jews brought light and G-dliness into the world. The uninhabited wilderness became the dwelling place, for 40 years, of the millions of Jews who had just left Egypt, and the "unsown land" was blessed with water from Miriam's well, causing all kinds of plants and trees to flourish.
The commandment to count the Levites charged with transporting the Sanctuary underscored and gave spiritual strength to this higher purpose - the transformation of a wilderness into an inhabited land. This, too, is the responsibility of every Jew, in every era, no matter where he may live, to transform and elevate his surrounding by infusing them with holiness. If at times it appears that insurmountable forces surround us, we are to remember the mission with which we have been charged and the special G-dly powers we are given to accomplish it. Just as the Children of Israel traveled from place to place by Divine command, so too is every Jew, by Divine Providence, faced with precisely those obstacles and challenges he is charged with overcoming. The Torah assures us that through our actions, we can succeed in turning any wilderness into a flourishing dwelling place for G-d.
We also learn from the fact that the Levites were not counted or required to carry the Sanctuary until the age of 30, that it is never too late try to improve oneself. Even if our behavior has been less than admirable and undisciplined - in the category of "wilderness" - we must never become dejected and despair of achieving our spiritual goals. Once the decision to improve is made, G-d gives us the strength to serve Him, purify ourselves, and uncover the G-dliness concealed within.

Adapted from the works of the Lubavitcher Rebbe.