Do you know the meaning of 4 candles?

In western culture, when christmas season comes, people light candles.
We can see very various ornaments with candle, like candlesticks, candle cups, etc.
But many Korean people don't know why the candlesticks or ornaments are 4.

Thanks to Sook, my lovely friend,
I've found out why 4 candles are needed.

From what Sook said, 
at the first week of December, when Christmas season begins, people light the first candle.
And at the second week, they light the first and second candles.
And at the third weed, they light 3 candles, and the at the fourth week including Christmas day, they light all the candles, 4.

This is the reason 4 candles are needed at Christmas season.