Answer: On Yom Kippur we limit ourselves with five kinds of restrictions, not only for eating. All the restrictions apply to the reception of pleasure, but we then want to bestow and not receive.
Yom Kippur symbolizes our willingness to carry out our mission and the same restrictions that we are ready to make to unite among ourselves and unite the whole world.
In this manner we discover our uncorrected egoistic desires. After we have examined them, repenting and regretting them during the Ten Days of Repentance, from the beginning of Rosh HaShanah until Yom Kippur, we clarify how much these desires are uncorrected. So we promise to correct ourselves, but the final correction happens on Purim.
From Yom Kippur until Chanukah we correct our desires of bestowal, meaning the first and easiest part of our ego. And so this holiday is called, “Chanu-Kah” (camp here), meaning an interruption, a rest.
From Chanukah until Purim we correct the greater desires. Purim corresponds to Yom Kippur (“Ki-pur” means “Like Purim”). This means that on Yom Kippur we are already preparing ourselves for Purim, for the full correction of our ego, of our entire evil nature, until it is impossible to discern any evil.
So on the Purim holiday we act completely opposite compared to Yom Kippur: unlimited drinking and eating.
But on Yom Kippur our desires are not yet corrected, and we can not be allowed to use. We cannot be happy, cannot eat, cannot drink, cannot fulfill ourselves. This is because all of our fulfillments are egoistic, with thoughts only about ourselves.
But if we gradually correct our desires, then we are freed from limitations and reach a state where everything is allowed for us! This is what the Purim holiday symbolizes, the completion of correction.
We must reach this state through connecting with others. So on Purim it is customary to send gifts to each other, something that testifies to our correction and readiness to relate well with everyone.
It follows that Yom Kippur is the starting point of the process of correction in the relationships between people. And the story of the prophet Jonah teaches about the obligation of the people of Israel, besides personal correction, to bring all the nations of the world to unity.
It is not worthwhile to rely on the possibility of fasting one day per year and through this erase all of our sins and iniquities that we committed throughout the year. It is said that the crimes against others are not forgiven on Yom Kippur if the injured person doesn’t forgive us.
We are all egoists and think only about how to do as much good as possible for ourselves; on account of this, we exploit the whole world that surrounds us; we want to profit and receive from everyone. Only fear of punishment somehow forces us to balance what we receive with those around us. But deep in the soul, we are completely indifferent to them and the whole world could burn, the main thing is concern about ourselves.
And we need to transform this attitude into an opposite attitude, so that we will connect and unite with everyone and things will be better for everyone. Only then will the upper force, the Creator, dwell among us and spread a canopy of peace over us.
From the Israeli Radio Program 103FM, 9/20/15