Purple is used to symbolize the love that comes through Christ. This third Advent candle represents the joy that the shepherds felt when they found out about the coming of the Messiah. It is also ...

On the third Sunday of Advent, it is traditional to celebrate Joy with the “Shepherds” candle. This third Sunday is also called Gaudete Sunday, and a literal translation here is to “rejoice.” ...

But it has nothing do with narrowness." The third Advent candle is about Joy. There's certainly a lot of it in New York City, though it's considered one of the most secular places in the world.