He explains by quoting the Bach who writes that in the days leading up to the miracles of Chanukah, the problem facing the Jewish People was rooted in their deteriorating service of Hashem, which in turn caused the assimilation of the Hellenists into the Greek culture. Their salvation was in accordance with the decree, and it was brought about through being moser nefesh to guard the kedusha of the Torah and its commandments, thereby meriting a unique display of siyata dishmaya - the miracle of finding a jug of oil intact, and the oil burning for eight days.
The pattern is apparent. There was a weakening in our service of Hashem, and He brought a decree against us measure for measure in order that we realize the reason for the punishment. Therefore, when we were moser nefesh to strengthen the kedusha that was lacking, we merited siyatadishmaya that brought salvation.
The concept is mirrored in the story of Yosef. Just as we refer to Avraham as the pillar of chesed, Yitzchok as the pillar of gevurah and Yaakov as the pillar of emes, so too Yosef is referred to as the pillar of kedusha - holiness and purity. It was he that was tested by being sold into the most depraved society in existence and it was he that was tempted by his mistress for years on end. However, for twenty two years in Mitzrayim he stood his ground, and hiskedusha stayed intact. He was moser nefesh to guard hiskedusha and Hashem gave him siyata dishmaya in everything he did. Potiphar, the jail warden, and even Pharaoh all sensed that Hashem was with him and hence all of them placed Yosef in positions of authority.
This is the common denominator between Chanukah and Yosef. When one is moser nefesh for kedusha, nothing can stand in his way. He is granted siyata dishmaya that brings salvation from and sovereignty over all those who stood against him. This was proven true with the mesirus nefesh of the "kohanecha ha'kedoshim" at the time of the miracle of Chanuka, and many years before that era when Yosef, the pillar of kedusha, was sold to Mitzrayim.
Chanukah is the Yom Tov which is most conducive to strengthening our avodas Hashem. If we were spiritually worthy, we could gain chizuk that would carry us throughout the year - to even a greater degree than what we gain from Rosh Hashana and Yom Kippur! Unfortunately, often the opposite is true and much of Chanukah has turned into wasted time. Let us try to glean some of what Chanukah has to offer and make an added effort to strengthen some aspect of our avodas Hashem that could use some improvement.