From a historical perspective; the Gospel of Luke focuses more on the details regarding the birth of Jesus from Mary's point of view (after all, Luke as a historian had access to interview Mary), while the Gospel of Matthew focuses more on the details through Joseph's point of view. What the birth of Jesus Christ (and the whole point of Christmas) actually means: God provided His son so that we may have peace with Him. Why? Because when you do not have the Son, the wrath of God remains on you because your wrongdoing estranges you from Him. Jesus was sent to this earth from God to save us from our sins and to open a channel that would grant everyone who believes in Him, direct access to God (John 14:6). In that access, God calls us to a different life, one that saves you here and now from the subjective force and power of this depressing, demanding, destructive, distressing, and evil world. Either way you slice it, Salvation is the greatest gift a soul could ever need, and the most costly gift of anyone could ever comprehend.