**Breishit / Genesis 25:34:**”And Eisav (Esau) despised the firstborn’s birthright.”
Rashi’s commentary:
The verse testifies to his wickedness, for he despised the service of the Omnipresent.
Most of the severe punishments of *Karet* (spiritual excision) are connected to the service of the Temple.
There are people who view the Holy Temple as a source of death. This is exactly the perspective of the sons of Israel in the Torah portion of Korach:
“Whoever approaches G-d’s Tabernacle dies! Are we then doomed to die?” (Bamidbar / Numbers 17:28).
Such a perspective is a continuation of the path of the wicked Eisav.
We, however, wish to follow the path of our forefather Yaakov (Jacob), not of Eisav.
We see the Holy Temple as the source of life for the entire world.
Translation of the words of Rabbi Eliyahu Weber at https://har-habait.org/article/589
Editor’s comment: At that time in history the Divine services that would later be given to the sons of Aharon (Aaron) were given to the Firstborn.