לרפואת פרץ ישראל בן בתיה קיילא בתוך שח"י
The gemara says that from the fact that the death of the sons of Aharon is mentioned in the context of the laws of Yom Kippur we derive that just as Yom Kippur atones for our sins so does the death of tzadikim.
The gemara says that when shedding tears over the passing of an upstanding person [אדם כשר] one earns forgiveness from all of his sins.
Once the person died - that already provides forgiveness. What does the shedding of tears add?
The answer may be that the death of a tzadik does not atone for sins for which one is liable for kares and capital punishment just as Yom Kippur does not [Yoma 86]. That is afforded then by the act of crying over the demise of an upstanding person.
The Zohar Hakadosh says in Acharei Mos [57b] that if one feels pain over the death of a tzadik or cries, G-d announces that his sins are forgiven and not only that but his children will not die in his lifetime.
The gemara also talks about how critical a meanningful eulogy is to us and to the niftar [Bava Metzia 86a Shabbos 153a]. The implication of the gemara elsewhere [Yerushalmi Yoma 1/1] is that death brings Divine blessing and the eulogy is like a second death which generates more Divine blessing.
The idea is that the greatest pleasure is when one has a תשוקה - a passion to achieve. No matter how much one has, if he lacks תשוקה for more, then he lacks simcha and vitality. You finish a masechta - you are so revved up to finish another. You do a chesed - you feel so good it gives you an appetite for more. You had a good experience davening in a certain shul for selichos or the yomim noraim - you make plans to go back there a different time. In gashmiyus it also works this way. No matter how much a person has, he naturally thinks of new areas to conquer. More money, more success - EXPANSION. That is the material, less holy reflection of man's nature to desire more and more.
That is really what the world to come is about. The pleasure is when the soul knows that he will be receiving greater and greater reward. ילכו מחיל אל חיל - The gemara says that tzadikim have no rest both in this and the next world. There is a constant expansion of their reward which creates a passion for what is coming up.
משכני אחריך נרוצה - The request is that we constantly run after Hashem. Even after we get there - הביאני המלך חדריו, we are not satisfied - נגילה ונשמחה בך נזכירה דודיך מיין ומישרים אהבוך, We rejoice in you and have an unrestrained love. We love you more than wine, we love you sincerely. We are "high" on HKB"H and can't get enough. We just want more and more.
When we hear a eulogy it is designed to create within us this passion and desire not to suffice with whatever we have achieved spiritually in this world to to strive for more and more. This brings a great aliyah to the neshama of the niftar and to our own neshamos.
This year we lost numerous tzadikim [e.g. Rav Vosner, Rav Chaim Greineman] both famous and less famous. One avoda of these days is to ponder and feel their loss, read about them and to be inspired by their spiritual accomplishments so that we too can reach exalted levels of Avodas Hashem.
[מבוסס בחלקו על הספד שאמר הגרי"מ חרל"פ שצ"ל על הגאון ר' דוד קרלינר בחורבות רבי יהודה החסיד בפני גדולי ישראל ועם רב]