For us I suppose, without being too pedantic, the symbolism of light is a bit more easy and a bit more immediate to understand. Although here in Australia and also because we have electricity we are used to light and plenty of it whenever we want it. And for the thousands of years when there was no electricity, no lighting by gas, I suggest that the symbolism of light, Christ the light of the world, would have been much more powerful than it is today. The light of candles, the people would have realised more easily, represent the eternal light of Almighty God which bathes all creation and drives away all evil shadows. Jesus himself is the true light, the daystar, the source of energy and activity and fruitfulness who came into the darkness where growth and happiness were so difficult and sometimes impossible.
Light also is a symbol of the glory which is to come.
The light of God which we shall all share when we are with the Trinity. In that sense we are under an obligation always to press on towards the light. For those with the gift of faith we should be grateful for that because billions and billions of people in the past and also today have passed their whole life without the light of revelation. I grew up in a time when the whole language and ethos of progress was much stronger than it is today. It is a different world today, the prizes are certainly greater for a minority but there is much more instability and uncertainty.