The eternal lights of Chanuka have eternal messages for us:
The candles are kindled when the sun sets. When darkness falls outside it is then time to light up our homes with the holy Chanuka lights, symbolizing the eternal lights of Torah and Mitzvos.
The location - that they be visible also outside - further indicates that the Torah and Mitzvos not be confined within the walls of the home, but must shine forth also outside.
Another important lesson is that however satisfactory the observance of Torah and Mitzvos may be on one day, a Jew is expected to do better the next day, and still better the day after. There is always room for improvement in the matters of goodness and holiness, which are infinite, being derived from The Infinite.
This too is emphasized by the Chanuka lights. For to fulfill the Mitzva of candle-lighting on the first night of Chanuka is to light one candle, yet the next night of Chanuka it is required to light two candles, and when another day passes even the higher standard of the previous day is no longer adequate, and an additional light is called for, and so on, to increase the light from day to day.