"The story of Christmas celebrates the fulfillment of God's promises and the incarnation of God in human flesh. That meaning is memorably captured by John 3:16. God loves, and God gives in order to save... It meant giving rather than getting, and Christ gave until He was empty; but His obedience led to an empty tomb and ultimate vindication that will culminate when throngs in heaven and on earth and under the earth, not just a host of angels, will bow down and sing glory in the highest to the One whose name is above every name."
David Garland, Luke - Exegetical Commentary, p. 129-130.