Each chag (Holy Day) or particular time of the Jewish calendar releases its unique and specific potential that is accessible to all.
This potential is the same that was released when the original event unfolded. We must be aware and appropriately prepare ourselves to access it in order to grow spiritually.
In the second century BCE, the Holy Land was ruled by the Seleucids (Syrian-Greeks), who tried to force the people of Israel to accept Greek culture and beliefs instead of mitzva observance and belief in God. Against all odds, a small band of faithful but poorly armed Jews, led by Judah the Maccabee, defeated one of the mightiest armies on earth, drove the Greeks from the land, reclaimed the Holy Temple in Jerusalem, and rededicated it to the service of God.
The potential reiterated each year during Chanuka is for us to transform the darkness into light, i.e., to see how the light can be extracted from the darkness itself.
Darkness is the place where Hashem hid the primordial light. This light was so precious; He wanted to prevent it from being used by the weak.
On Chanuka, we are granted access by Hashem to a particular channel of energy which provides us an enormous boost to overcome our own yetzer ha’ra (evil inclination). Each person has his/her own specific weaknesses which need to be rectified. The light of Chanuka helps us fight and prevail over our own yetzer ha’ra.