Existence is a fusion of time, space and consciousness, and all have associations with light.
Hashem created time. Time is measured in increments of 7, culminated by Shabbos. Shabbos is welcomed with candles.
Hashem created the universe. Within it, the earth, within it Israel, within it Jerusalem, within it the Beis HaMikdash, containing the Menora. This relates to space.
Hashem created life. Within it, the human race, within it the nation of Israel, within it Levi, within it the Kohanim, and ultimately, the Cohen Gadol, whose job includes lighting the Menora.
The light is symbolic of Hashgacha Klalis, Hashem’s supervision in a general sense, over all things. But on Chanuka, we light individual lights, each person for themselves. The light is lit at the door, indicating that our comings and goings, our entire lives, are for the sake of Heaven.
What Chanuka changed was that we show that each person can have connection, a Hashgacha Pratis. We just have to seek it out.
In parentheses, the Ishbitzer adds that there are three mitzvos that are disqualified if they are too high; Sukka, Eruv and Menora. They respectively relate to space, time, and consciousness. They have to be related to in a personal, individual way, and Chanuka shows the way.