Most of us generally associate Chanukah with the nisim of the military victory and the oil as well as various mitzvos and minhagim surrounding them. However, looking deeper, we see other inyanim at play, in particular tefillah, the unity of Hashem, and the identity of Klal Yisroel. It starts with tefillah. Not only do we today add special tefillos for Chanukah that commemorate the events of the past, but the Avos themselves davened for the welfare of the yidden for the events that would take place in the future. Rav Elimelech Biderman, shlita, brings Rav Menachem Nochum Twersky of Chernobyl (18th century) to explain. At the akeidah, Avraham said, וַיֹּ֨אמֶר אַבְרָהָ֜ם אֶל־נְעָרָ֗יו שְׁבוּ־לָכֶ֥ם פֹּה֙ עִֽם־הַחֲמ֔וֹר וַאֲנִ֣י וְהַנַּ֔עַר נֵלְכָ֖ה עַד־כֹּ֑ה וְנִֽשְׁתַּחֲוֶ֖ה וְנָשׁ֥וּבָה אֲלֵיכֶֽם (Bereishis 22:5). “Then Abraham said to his servants, “You stay here with the ass. The boy and I will go up there; we will worship and we will return to you.” The word כה has the numerical value of 25, hinting at the 25th of Kislev, when Chanukah begins.
Yosef HaTzadick offered similar tefillos. We see this in the posuk וַיִּשָּׂ֣א עֵינָ֗יו וַיַּ֞רְא אֶת־בִּנְיָמִ֣ין אָחִיו֮ בֶּן־אִמּוֹ֒ וַיֹּ֗אמֶר הֲזֶה֙ אֲחִיכֶ֣ם הַקָּטֹ֔ן אֲשֶׁ֥ר אֲמַרְתֶּ֖ם אֵלָ֑י וַיֹּאמַ֕ר אֱלֹהִ֥ים יׇחְנְךָ֖ בְּנִֽי (Bereishis 43:29). “Looking about, he saw his brother Benjamin, his mother’s son, and asked, “Is this your youngest brother of whom you spoke to me?” And he said, “May God be gracious to you, my boy.’” יחנך, be gracious, alludes to חנוכה.
So not only do our tefillos to Hashem connect us to our ancestors who battled the Syrian Greeks, but they connect us to the Avos who davened on behalf of their descendants in their struggle against the Syrian Greeks. Our tefillos on Chanukah take us all the way back to the Avos. We all meet, with the Avos going 1,600 years into the future, and we going 2,161 years in the past. We are one nation, not only in any one era, but across eras. Hashem Echad, the unity of Hashem, is reflected in the unity of His people across time and space.