Our Sages consider the Sin of the Spies even worse than the Sin of the Golden Calf. What is the root cause of the sin of rejection of the Land of Israel? What is so terrible about "We will make a new leader and return to Egypt?" At the time of the sin, as Rashi explains, the spies were righteous Jews who had just experienced the myriad miracles of the Exodus from Egypt and the journey through the desert. Did they really believe that G-d could not humble the lowly Canaanites as He had the mighty Egyptian empire? How could they so severely miss the mark?
There is a difference between the Exodus from Egypt and the entry into the Land of Israel. The entry into the Land of Israel brings with it an entirely new reality. G-d took care of Pharaoh by Himself: "G-d will fight for you and you, remain silent," G-d told the Israelites at the edge of the Red Sea. But for the Canaanites, the approach is different: Both the Israelites and G-d will be in the fight.
As soon as the Jewish People enters the Land of Israel, the manna stops falling from the heavens. In the Land of Israel, we must plow, plant and harvest. We must live a life of action and bring the manna down from heaven by ourselves in full cooperation with the Creator. That is the message of the Jewish Nation. It is a message that cannot be applied without the Land of Israel. It is the message of perfection of the world in the Kingdom of the Almighty.
The Sin of the Golden Calf, although totally unacceptable, was easier to rectify. The Israelites were punished, repented and returned to G-d. The Sin of the Spies is much more difficult to eradicate and rectify. It is not a tactical sin but a rejection of the entire purpose of the Jewish Nation. It is a strategic sin a strategic error of cosmic proportions. It is a lack of understanding of the goal of the journey, the loss of the purpose for our very existence.
The resolution of the conflict between the material and spiritual has tormented humanity from time immemorial. The Western approach is to nullify the material in order to be holy. The Moslem approach is to wallow in the material in order to be holy. On the Festival of Tabernacles, the 70 nations of the world bring their holiday offerings to the House of G-d in Jerusalem. But there is one offering that only Israel can bring. It is the shlamim (wholeness) offering. Half of it is to be eaten by the people and half is for G-d. It is the offering that is irrelevant to a non-Jewish reality. The secret of the unification between the holy and the mundane was given to Israel alone.
There is only one way to resolve the conflict between the spiritual and the mundane. Only when the Jewish Nation lives in the unique Land chosen for it by the Master of the Universe and crowns the spiritual G-d over the material world at their fusion point in Jerusalem, at the Royal Palace, the Holy Temple will the world live in peace and serenity.
By attempting to return to Egypt, the Israelites effectively sent the entire world into a helter-skelter tailspin. No wonder that the consequences of that ill-conceived error are still plaguing us today.
The Sin of the Spies smolders in all sectors of Jewish society throughout the generations. It infects every person who excludes himself or G-d from even one aspect of our holistic reality. It infects those who cling to G-d to the exclusion of the Land of Israel and those who cling to the Land of Israel to the exclusion of G-d. It infects the person who studies Torah but does not work, the person who does not study Torah and only works, the person who does not settle the Land, the person who strictly settles the Land, the person disassociated from politics, the person who deals only with politics; any attachment to partial reality conceals within it a touch of the Sin of the Spies.
The solution is to open ourselves to the entire spectrum of our reality - and to perfect the world in the Kingdom of the Almighty.