Advent embraces the whole arc of the Christian cosmology.
The Bible begins in darkness. "In the beginning . . . the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. And God said, “Let there be light,” and there was light" (Gen 1:1-3).
Darkness, and light.
Then, "In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made. In him was life, and that life was the light of all mankind. The light shines in the darkness, and the darkness has not overcome it. . . . The true light that gives light to everyone was coming into the world. . . .The Word became flesh and made his dwelling among us" (John 1:1-14).
Darkness, and light.
Finally, "I heard a loud voice from the throne saying, "Look! God's dwelling place is now among the people, and he will dwell with them. They will be his people, and God himself will be with them and be their God. He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away. . . . The city does not need the sun or the moon to shine on it, for the glory of God gives it light, and the Lamb is its lamp. The nations will walk by its light, and the kings of the earth will bring their splendor into it. On no day will its gates ever be shut, for there will be no night there. . . .There will be no more night. They will not need the light of a lamp or the light of the sun, for the Lord God will give them light." (Rev 21:3-4, 23-25; 22:5)
Darkness, and light.
God's light broke into darkness at creation. God's light broke into darkness at Christmas. God's light will break into darkness at the end. And in every moment between - God's light is breaking into darkness.
This world is cyclical. Darkness, and light. Darkness, and light. Darkness, and light. We continually experience darkness. And God’s light continues to break in.
Advent remembers the ways that God has broken into our darkness in the past (Christmas). Advent acknowledges that we still live in a world of darkness. Advent hopes that God will break into darkness again. Advent hopes. Advent hopes. Advent hopes. Advent remembers the First coming and clings to the promise of the Second Coming.
“Because God has been faithful and kept His promises in the past, we can hope with confidence that God will keep His promises to us in the present and in the future” (Dieter F. Uchtdorf). In Advent, we look back. We say, “Yes. God has kept God’s promises. God has been faithful.” supported by the security of God’s past faithfulness, we turn our gaze forward. We say, “Yes. God will keep God’s promises. God is faithful. God will not leave me alone.”
Advent is a time of darkness. And yet, each Sunday we light a candle. Light. Through the darkness of this season, God gifts us with glimmers of light. Through the darkness of our mortal sojourn, as we wait for God to make all things right, God gifts us glimmers of light. Our life is a constant cycle of darkness and light. Advent reminds us that God’s light will always break in.