There are two holidays in which we celebrate the deliverance of the Jewish people in post-biblical times, Chanukah and Purim. Yet they are celebrated in very different ways. On Purim the focus is on celebrating the miracles which occurred through which Jewish people were saved.
We read the Megillah which tells us the story of our miraculous deliverance and we celebrate by making a festive meal and giving out gifts. While on Chanukah the main observance that the sages enacted was to light the Menorah. This reminds us of the miracle that took place with the Menorah in the temple. Yet it doesn’t tell us anything about the miraculous victory of the small and weak Maccabean army against the large and mighty Greek army.
We can explain this difference by understanding the different nature of the decrees against the Jews on Chanukah and Purim. In the time that the story of Purim took place, Haman hated the Jews and convinced the King Achashverosh to annihilate the Jewish people.
However, in the times of the Chanukah story, we can’t find that the Greeks hated the Jews. On the contrary, they tried to convince the Jews to adapt to their Hellenistic culture. The Greeks were great philosophers and they believed that reason should dictate how a person should behave. They were bothered by the fact that the Jews believed that the G-d’s Torah should dictate their behavior. So they set out on campaigns to force the Jews to accept their lifestyle.
This is the reason that Chanukah is celebrated by a Menorah. The light of the Menorah in the temple, was symbolic of the pure and holy light of our Torah, and on Chanukah, we celebrate the gift that the Greeks were unable to take away from us.