For there is born to you, this day, in the city of David, a Savior, who is Christ the Lord.
The Lord ...  The preference Luke showed for this title in his record of Jesus' life and teachings is alleged by the critics to have been the cause of his using it in such contexts as this, "retroactively," thus denying that Luke really reported here exactly what the angels said.  Such a view is totally unworthy of acceptance.  Rather, it is in the use of the term "Lord' by Elizabeth and by the angels, etc. which accounts for Luke's preference for it.  This Gospel was written only thirty years after the events related; and the widespread use of "Lord" as a title of Jesus Christ, as evidenced by the writings and preaching of Paul, with whom Luke had been a traveling companion for many years, postulates that there was a cause for such widespread acceptance of the title; and that cause is evident in the event here, in which the angels of God called Jesus "Lord."