After the episode of the מרגלים, the Jews are given 2 mitzvot: נסכים and חלה. Chazal say this was by way of reassurance that they would eventually reach ארץ ישראל. But why these particular מצות?
As far as נסכים: Associated with שירה, אין אומרים שירה אלא על היין . Promise of joy; even they now they are נזופים למקום, in a state of נידוי לשמים, eventually their relationship with הקב"ה will again be characterized by joy and song.
What about חלה?
What was motive of מרגלים? One answer, suggested by R' Shneur Zalman of Liadi, the בעל התניא: Wanted to stay in dessert, under ענני הכבוד in spiritual Utopia, eating מן and מי באר, שמלתם לא בלתה etc., no need to occupy themselves with physical needs. (מרגלים were leaders of that generation, apparently men suited to that utopian milieu).
But - purpose of Torah not for Utopia, but to be learned and observed in this world, and to infuse it with רוחניות, make it a place fit for the resting of the Shechina.
חלה - unlike other מצוות התלויות בארץ which did not go into effect until 14 years after the Jews entered ארץ ישראל, when it acquired the קדושת ארץ ישראל as recognized by halachah - went into effect as soon as they entered ארץ ישראל. Also - שיעור of dough required for חלה is identical to the amount of מן that fell to each Jew in the dessert - one עומר. Apparently, חלה expressed our gratitude that we no longer need מן, because we can take the לחם מן הארץ, the עבור הארץ, and transform it into לחם מן השמים, back into מן.
So חלה teaches the lesson that the מרגלים failed to learn; and it represents the reassurance that the people, or at least their children, would learn that lesson.
No one of us lives in utopia. Everyone has hardships and difficulties. It is always tempting to say: If I had more - time, money, peace of mind - I would learn more, involve myself more in Yiddishkeit. But Torah is meant to be learned and lived in just those difficult situations, and to transform our lives thereby into something meaningful, and if we do that then our lives will be infused with joy and song.