Christians today, at least those of us in the US, seem to rush to Christmas at the expense of Advent. We sing "Joy to the World" from the very beginning of December. While it is good to celebrate the Savior's birth, Advent isn't really about joy to the world. Advent is about waiting - waiting for the Messiah- waiting for deliverance.
Advent is more where we live, as we wait for heaven - wait for Christ's return - wait for the promises of victorious living to be fulfilled in us.
Elizabeth's waiting for a child is a perfect symbol of Advent. She waited so many years. She hoped against hope, and no doubt wondered why God was denying her the blessing of a child. But God is faithful, and God loves us - while we wait.
Related scriptures:
Ephesians 3:19-20 Isaiah 40:31 Luke 1:5-25 Psalm 37:7 Psalm 5:3