In the Gospel reading (Luke 3:1-6), Luke sets the scene in detail. Throughout salvation history, God reaches into our time and space to act in history. As the Catechism puts it, "(t)he witness of Scripture is unanimous that the solicitude of divine providence is concrete and immediate; God cares for all, from the least things to the great events of the world and its history. The sacred books powerfully affirm God's absolute sovereignty over the course of events..." 
Christ is the perfect revelation of God, and as we experience the Advent and Christmas readings we'll see how God acts in human time and space - in "concrete and immediate ways" - to save us. Our Advent hymn today, Verbum Caro Factum Est, reminds us of God's incarnation in a particular time and place, and in His eternal glory.
Verbum caro factum estThe words come from the beginning of St. John's Gospel (John 1:14):
Et habitavit in nobis
et vidimus gloriam ejus
gloriam quasi unigeniti a Patre
plenum gratiae et veritatis.
And the Word became fleshAs we prayed in the psalm response on Sunday, "the Lord has done great things for us". (Ps 126:1-6) If you catch a Sunday football game after Mass, maybe you'll see a sign with that famous summary of John's: "For God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life." (John 3:16) This is the greatest thing God has given us in the long history of our salvation - our salvation through Jesus Christ.
and made his dwelling among us
and we saw his glory...as of the Father's only Son
full of grace and truth.
God has given us immeasurable gifts, and He continues to give to each of us individually. Take time today to consider the gifts God has given you, the ways that He is at work in your life. Make St. Paul's prayer for the Phillipian church (Phil 1:4-6, 8-11) your own today:
Lord, this is my prayer:
that my love may increase ever more and more
in knowledge and every kind of perception,
to discern what is of value,
so that I may be pure and blameless for the day of Christ,
filled with the fruit of righteousness
that comes through Jesus Christ
for the glory and praise of God.