Luke give us no other option. Advent requires us to stand with the oppressed, poor, and outcast.
Luke 1 is the chapter of waiting. Most churchgoers recognize the start of Luke 2, "And it came to pass in those days, that there went out a decree from Caesar Augustus, that all the world should be taxed," but too often, especially in denominations which have no lectionary, Luke 1 is downplayed. There is so much to unpack in Luke 2 and Matthew that this portion is thrown in as backstory, perhaps taking up one Sunday as background surrounding the annunciation of Mary.
There are three named characters in Luke 1, the characters with whom we wait: Mary, Elizabeth, and Zechariah. All three of them wait for the same thing, the overthrow and reversal of a world which is unjust and unrighteous. When Elizabeth becomes pregnant, we see this reversal first for her, as God "has shown his favor and taken away my disgrace." (v. 25) In a society which saw infertility as an act of God against that individual, the disgrace of what was supposed to be God's judgement is replaced with God's favor. It is a complete reversal of favor, and we are taught that what we say about God is not always the case.
Next, when Mary visits Elizabeth, we hear her song. In the Magnificat, she identifies herself first and foremost as a slave of not just humble, but humiliated status. (v. 48) An unwed mother, she surely heard the gossip, slurs, and shame surrounding her. She was not just humble; she was humiliated. She waits for her child because she knows this will be reversed. She says that God "has brought down rulers from their thrones, but has lifted up the humiliated," using the same Greek root as her humiliation. Mary recognized what was happening. She, as the Mother of God, was to be placed above earthly leaders who would be cast down, even in her humiliation, and others in similar situations would be too.
Mary and Zechariah's songs also describe the coming reversal of fortunes, not just of individuals but Israel and the world as a whole. The humiliated have not just found triumph over the powerful. God has "filled the poor with good things, but has sent the rich away empty." (v. 53) Israel will find help to overthrow her enemies and live "in holiness and righteousness" without fear of an oppressive empire. (v.74-75) And "those living in darkness and in the shadow of death" will find the favor of God shining on them too. (v. 76)
Mary, Elizabeth, and Zechariah knew this had happened before, in the Exodus, the return from Exile, and throughout God's narrative with Israel, but these changes did not just end with the birth of John and Jesus. Mary reminds us that God's "mercy extends to those who fear him, from generation to generation." (v. 50) These are not just the events of the past. This reversal of the oppressive order is for everyone in every era. The mighty works and favor of God are not manifested so we can have twinkling lights, festive buffets, brightly wrapped gifts, and eggnog. The favor of God in Advent rests with the single mother on food stamps in the Bronx. God's mighty arm is for performing great works for the Syrian refugee and Honduran immigrant. The homeless on the streets are in waiting for when the wealthy are finished storing up God's wrath against themselves.
God also does not just want this liberation to happen through miracles and sorrowful waiting. The Gospel of Christ's incarnation, death, resurrection, and return has fulfilled the promise of Zechariah. We can work for righteousness without fear, empowered by the Gospel, and God's light will illuminate our path. Luke gives us no other option. We either participate in the Gospel that cleanses away sins, both personal and societal, or we will also be condemned by God's righteousness. We can stand up for the poor, reverse the fortunes of the oppressed, and welcome in the outcast. If we do not do that, we cannot be joyfully awaiting Christ's return as symbolized in Advent. We must instead be afraid, for God will cast us to the dirt and send us away empty too.