I totally agree, Jeremy. Matthew in particular slathers the story of Jesus with scriptural references. These usually have no messianic expectation in their original context, including Is. 7:14. "Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel." In isolation it fits both Matthew and Luke's birth narratives.

But then the next verses make it clear that this is a prophecy for ancient Israel:

15 Butter and honey shall he eat, that he may know to refuse the evil, and choose the good.16 For before the child shall know to refuse the evil, and choose the good, the land that thou abhorrest shall be forsaken of both her kings. [KJV]

I submit that this, among other examples, confirms your point.

However, I am NOT saying that the virginal conception of Jesus is just a myth. Its meaning is essential. Jesus was not a premarital accident, but appears among us as part of God's will for us and all creation.

Thanks again for your clear articles.