The Satmar Rebbe, in Yitav Lev, interprets the sin of the spies from a personal perspective. As a rule, when a person enters Eretz Yisrael, he experiences a spiritual decline at first. However, this descent is for the purpose of ascent, and in the end he will rise above his prior spiritual level.

There are two reasons for this:

"Whoever is greater than his friend, his [evil] inclination is greater than his." (Succah 52a) Therefore, the evil inclination of a person in more powerful in Eretz Yisrael than outside of it, so that special effort is needed in Israel not to stumble.

As with medicines, which draw out the sickness and contagion from the body, there is danger that if the treatment is stopped in the middle, the person will remain having lost on both accounts -- he suffered the painful treatment, and the infection will remain.

When a person first enters Eretz Yisrael he will sense a spiritual decline, as the contagion from his years outside of Israel is drawn out, until it leaves him. However, if he does not follow through, the suffering will remain without being healed.

"Avraham journeyed on, journeying steadily toward the south. There was a famine in the land, and Avram descended to Egypt." (Bereishit 12:9-10) "Avram went up from Egypt." (13:1) The Masorah notes: "diminishing steadily," "returning steadily." His journey in Eretz Yisrael at first caused him to diminish, so that he declined from his level, until he descended to Egypt. However, in the end, he returned: "Avram went up from Egypt ... He proceeded on his journeys ... to the place where his tent had been at first" (13:1-4) -- he returned to his prior level.

The same is true regarding the spies. Immediately upon entering the Land they sensed a great spiritual decline. Moshe hinted to them, "Go up here in the south and ascend the mountain" (13:17)-- they should be wary of declining. Rashi alludes to this when he comments: "This is the practice of merchants, they show the inferior quality first." The initial decline is the manner of treatment to draw out the contagion, and thus -- "You shall strengthen yourselves." (13:20)

However, the spies, who immediately sensed the decline and loss, informed Bnei Yisrael that the nature of the Land is to cause decline: "They went and they came ... and brought them back a report." (13:26) They brought themselves as proof. [Cf. Rashi on the pasuk, "he will bring him -- he will bring himself" (Bamidbar 6:13)] "They showed them the fruit of the Land" (13:26) -- this is the result of entering the Land.

However, Calev responded to them, "We shall surely go up" (13:30), that this is all a descent for the purpose of ascent, refinement, and purification. However, the other spies said, "We cannot ascend," but rather we will descend, "for it is too strong for us." (13:31) Thus, they besmirched the Land, that it ruins its inhabitants and lowers them from their level.

"We were like grasshoppers in our eyes." (13:33) It is possible that they said this out of modesty, but it is not so! "And so we were in their eyes," because we actually did descend from our level, so that we were like grasshoppers even in their eyes. However, after Bnei Yisrael recognized that they sinned, "They awoke early in the morning ... saying, 'We are ready, and we shall ascend to the place of which Hashem has spoken, for we have sinned.'" (14:40) They understood that this is not a true decline, and therefore sought to return to the Land to ascend, but Moshe told them that it was now too late. "Do not ascend" (14:42) -- now is not the time for ascent, until the time of redemption comes once again.

Rav Charlop responded in a similar manner to one who complained that he felt more spiritual outside of Eretz Yisrael. Rav Charlop wrote back that outside of Israel a person has a smaller soul, and anything spiritual satisfies it. However, when entering the Land, his soul is elevated, and it does not suffice with the name nourishment that satisfied it outside of Israel. Therefore, the soul is depressed and causes dissatisfaction for the person. If he will try hard to provide the soul more that what he gave it outside of Israel, it will certainly feel calmed.

We now understand why only entering Eretz Yisrael is called aliyah (ascent)!