Chasidism explains that the spies did not wish to enter the Land of Israel because they did not want to become involved with the materialism of the world. Throughout the duration of the Jewish people's stay in the desert, they were free from such involvements: their food came from heaven (the manna); water they had from the miraculous "Well of Miriam"; they were sheltered by the Heavenly "Cloud of Glory." Thus, they did not wish to leave the desert to enter the Holy Land where they would have to engage in ploughing, sowing, and all other normative activities for their daily existence.
The spies' motive may have been sincere and spiritual, but it went counter to the Divine intent. G-d created the world in order to have a Divine abode in this physical world: man is to transform himself and the material world into a worthy abode for G-dliness. This is done by utilizing and interacting with every created substance for its Divinely intended purpose, thus elevating and sublimating it to a spiritual reality. That is why we were given the Torah and mitzvot (commandments), which enable us to achieve that goal. And that is our mission for the duration of the exile.
The Messianic era is the ultimate purpose of the creation. For then this physical world will demonstratably be a Divine abode, with G-d's Presence fully manifest and experienced. It will be a time of "neither famine nor war, neither envy nor strife, because good will emanate in abundance and all delightful things will be accessible like dust. The singular preoccupation of the entire world will be to know G-d. The Israelites, therefore, will be great sages and know the hidden matters, attaining knowledge of their Creator to the full extent of human capacity, as it is said: "The earth shall be full with the knowledge of G-d as the waters cover the sea" (Isaiah 11:9) (Hilchot Melachim 12:5).
This ultimate perfection of the Messianic era and the time of the Resurrection of the Dead depend on our actions and service of G-d throughout the duration of the exile. The sin of the spies was that they tried to circumvent the process of this refining of the physical world and preparing it for Moshiach.
Mundane entanglements, involvement with worldly matters, may be tiresome and distasteful for one who aspires to spiritual heights. They are, however, an integral part of the Divine plan, and as Chasidism explains: "The ultimate intent of the descent and exile is to prepare for an immense ascent when, in the days of Moshiach, the light of G-d will radiate in a manifest way!"
From Living with Moshiach by Rabbi J. Immanuel Schochet, adapted from the works of the Lubavitcher Rebbe
