The mood of Advent is that we are all lost. Advent isn't about the "saved" telling the "lost" to "get saved." Advent is a light that dawns in all of our darknesses. Advent is bread for all of our hungers. Advent is the promise kept for all of us promise-breakers, betrayers and failures.
Can we find a way to celebrate Advent as those who NEED to be saved? As those who NEED a savior? Not as those who know for certain that someone else does?
The key to Advent is not living as if we are the people of God and always have been. The key is to live as if we need a Savior, and he has come to us, found us, saved us and is there for everyone in the world.
The mood of Advent isn't "come be religious like us." It is "We are all waiting for our Savior to be born. Let us wait together. And when he comes, let us recognize him, together."
When the day dawns, let us all receive him. We go to the manger and worship. We give to him our gifts. We take his light to the poor.
Until then, we are the poor, the weak, the blind, the lonely, the guilty and the desperate. We light candles because we who are in darkness are in need of a great light. We need a savior.