Since many have undertaken to set in order a narrative concerning those matters which have been fulfilled among us,
Who from the beginning were eyewitnesses and ministers of the word ... Luke's mention of eye-witnesses of the things he recorded "from the beginning" and "from the first" (Luke 1:3), along with the conspicuous birth narrative in the first two chapters is very nearly the equivalent of saying that he had interviewed the Virgin Mary herself, a conclusion that will appear mandatory in the narrative itself.  This is devastating to the wild, subjective theories with regard to Luke's source for the first two chapters.  This is also the end of all attempts to late-date the Gospel; for, even at the time Luke wrote, the Virgin Mother was not less than eighty years of age, even allowing for the annunciation to have occurred when she was fifteen years old.