Carl, Isaiah 7:14 says "Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel" (italics added). If the word "virgin" had been mistranslated and should rather have read "young maiden," then that wouldn't be a "sign" from God. Every day, thousands of young maidens conceive. Only once has it happened to a virgin.Even though I do think Jesus was born of a virgin and even though I accept Matthew's assertion that Isaiah was in some sense prophesying a coming savior, I think we need to be honest with the text and realize that that was not ALL Isaiah was prophesying.
Ahaz, King of Judah during the late the 8th century bc, was being attacked by the nations of Aram and Israel and was considering appealing to the Assyrians for military assistance. Isaiah visited him and told him to ask for a sign from God that things would work out for the best. He refused, at which point Isaiah, frustrated, gave this prophecy:
"Therefore** the Lord himself will give you a sign; Behold, a virgin will conceive and bear a son, and she will call his name 'Immanuel.' The child will eat butter and honey when he learns how to refuse evil and choose good. But before the child learns to refuse evil and choose good, the land that you hate will lose both her kings."You may recognize the first sentence, it's the Jesus prophecy that Comfort refers to. But what's the rest of this? Its words are plain enough: a young child is going to be born and before he's old enough to know right and wrong, maybe three years, both of Ahaz's tormentors would be dead.
-- Isaiah 7:14-16 (my translation with help from King James)
The prophecy was given to Ahaz, at a specific time and for a specific purpose: he was to rely on God rather than on Assyrian arms, because his tormentors were temporary while the damage he could cause his kingdom would be permanent. Obviously in its immediate application, it's not remotely messianic except in the sense that God would deliver Judah (Immanuel means "God is with us"). We have no choice but to conclude that whatever sign this was to be, it applied primarily to the 7th century bc and would be fulfilled then, because otherwise the passage as written and the promise as given make no sense: what help is it to Ahaz's tenuous military situation that Jesus would be born 7 centuries hence?
Now, upon reading the whole passage, we have to ask, "What's the 'sign' that Ahaz would note?" Would it be that a virgin gave birth? It can't be, because Comfort correctly assures us that that's only happened once. Would it be that a young woman had a child? Nope, Comfort correctly notes that they have kids all the time. I submit to you at that the young woman and child is not "the sign" at all: the sign is that both kings would die, meaning that Ahaz had no need to seek outside military help***. The inclusion of the woman and child is simply a dramatic way of telling Ahaz when that would come to pass. The only way we can possibly attribute this to Jesus, born 700 years after Ahab and Isaiah were both dead, is because Matthew told us it was.
That being the case, I doubt that the virgin birth is meant to be a sign for us at all. While Matthew says it was done so what Isaiah said "might be fulfilled," he does not say that it's being done as a sign for us - he purposely leaves that part of the text out of his gospel. In fact, if it's supposed to be a sign it's a horrible one because no one but Mary was in a position to absolutely verify it.
None of this is meant to doubt the idea that Matthew was correct, he was: in some archetypal scheme unknown to me****, God was keeping a promise to the Jewish nation. But because none of us understands very well how exactly God went about that, I think that we as Christians need to be a whole lot more honest about the limitations of our own interpretations before we criticize others who find those interpretations unpersuasive.
* Yeah, the banana guy. I actually think the banana argument from design is one of the sillier arguments for creationalism that I've seen, if only because modern bananas are a result of thousands of years of human domestication and cultivation. Wild bananas don't look like the ones you buy in the store, so it's a little tough to argue that God created something because it's convenient to us, when it's convenient to us mostly because we have bred it to be so.
** The "therefore" refers to Ahaz's intransigence.
*** which he eventually did anyway (2Kings 16:7). It turned out to be a very bad idea in retrospect.
**** Matthew, John, and even Paul use an archetypal interpretive scheme that was common in 1st Century Judaism - using small snippets and key words to "illustrate" later events. That would look uncomfortably subjective were some person to do it today. I accept that they are correct because I have a prior acceptance of the New Testament as in some sense inpired. But that's not how we "do" prophecy in the 21st century.