Indifference
A question was asked regarding the first born, the בכורות, and the reason why they lost their special role to the Leviim. After all, it was the Eirev Rav, the mixed multitude, who were the instigators of the sin of the Golden Calf. Nevertheless, it was the חטא העגל that sealed their fate, and gave the Leviim the rights to serve and protect the Temple and the Jewish people.
Rabbi Twerski explained that the shortcomings of the בכור, was more than not heeding Moshe’s call of מי לה׳ אלי, “Whoever is for Hashem, come to me.” The Leviim heard Moshe, and the בכור did not.
The real reason why they lost this special role, was their indifference. They did not join Moshe and merely stood by and did nothing. There was a major crisis facing the Jewish people, and leadership and action was badly needed.
The most blatant form of indifference that the world has seen, was the indifference during the Holocaust, when many knew what was happening, and did nothing.
It is understandable that when Hashem such passivity and lack of initiative, He realized that these were not the ones needed to act with dedication and devotion towards His people.
This is clearly a lesson for us all. We must not be passive and indifferent to the needs of עם ישראל. We must act as the Leviim, and not the First Born.