How might Christianity have developed if the doctrine of the Virgin Birth had never taken hold?

Of the four canonical gospels, only Luke & Matthew claim that Jesus was born of a woman who had never known a man. I am not aware of any statements by the Apostle Paul that definitively make any such assertion either; and it doesn’t seem to me that the interpretation of the meaning of the Passion narrative or his ministry as a whole depend on Mary’s virginity (perpetual or otherwise).

How might the history of Christianity and Christendom be different if the doctrine of the Virgin Birth had never taken hold?

Paul makes no claims about a Virgin Birth.
I can’t see much different about the overall development of Christianity with this change. Certainly it would make a difference in the way Christians, especially Catholics, venerated Mary, but I think it would, at most, have taken an only slightly different form. She’d still be “Queen of Heaven” and Jesus’ Mother.

I very much doubt that Christian attitudes towards sexuality would have been significantly altered. The Christians were neither the first, nor the last, to bundle some very odd beliefs about sex into their faith. People seem to like doing that for some reason.

I also vote for mot much difference. I personally don’t see any “very odd beliefs about sex” in Christianity at any point. At this particular point in time, when our culture (at least in this country and western Europe) is hypersexualized, Christianity is notable for being a force against that. However, for much of its history Christianity was more notable for taking a positive view of human sexuality as compared to opposing religious viewpoints. This would be particularly true in comparing Christian views to those of the Manichees and various offshoots thereof.

Christianity decidiedly did not take a positive view of sexuality and only sanctioned it for reproduction. Christianity has never been noted for positive attitiudes towards recreational sex, unmarried sex, gay sex, group sex, etc.

Paul didn’t even like the idea of sex between married couples, said he would prefer that everybody else was “like me,” but took the attitude that it was acceptable if people really insisted.

The Manicheans were also Christians, by the way.
As to the OP, I don’t the VB doctrine is very important to Christianity, that religions always have hangups about sex and intepersonal relationships (churches don’t like what they can’t control), and that Christianity would have been just as puritanical and uptight without the VB doctsrine as with it.

No they weren’t. They were followers of a third century Persian prophet named Mani, and was derived more from Zoroastrianism than anything else. It was probably influenced by both Christianity and Judaism, but the Manicheans weren’t Christian.

Yep. I mixed them up in my head with Arians, for some reason. Brainfart.

Many Protestant sects don’t preach the idea of the virgin birth at all. The Congregational and Presbyterian churches I attended in my youth certainly didn’t. I distinctly recall one of the Presbyterian ministers explaining that Joseph was probably Jesus’ biological father, but that it didn’t matter, Jesus was divine anyway because heck God can do whatever he wants, right? Also that it would have been against Jewish custom at the time for Joseph and Mary to abstain from sex after they were married, so of course Jesus probably had siblings. It was also explained to us that the word for “virgin” in the original could also have been translated as “young woman” just as easily. I cannot vouch for that as I am not an expert in ancient languages.

Mary’s perpetual virginity as taught by the Catholics is not relevant. I left it out of the OP on purpose.

Matthew quotes from the Greek Septuagint translation of Isaiah 7:14 (“behold, the young woman will become pregnant and bear a son and she will call his name Emmanuel”). When the passage was translated from Hebrew to Greek in the LXX (c. 3rd century BCE), the Hebrew word for “young woman” (almah) was erroneously translated in the Greek word parthenos, meaning “virgin.” Matthew was a Greek who used the LXX as his OT source, and he used that mistranslation (along with a totally decontextualized reading of the passage. In context it has nothing to do with the Messiah) to extropolate his virgin birth.

There are several denominations within christianity that are distinctly non-christocentric. Not that they necessarily deny VB doctrine or the super-deity of Jesus Christ, they just don’t place much emphasis on it. One could probably look at these groups as examples of non-VB christianity. Unitarians, Jehovah’s Witnesses, some Quakers - in particular the Hicksites.

It seems like most Americans views of christianity come from either Catholics or the fundamentalist/evangelical/Baptist model. Understandable, as those are far and away the largest denominations in the country, and both are very strongly christocentric. Christianity as a belief system is much broader however. Most of the “christian” prohibitions, particularily in sexual matters, stemmed from a handful of early church fathers - Paul in particular. It is significant that Paul, who was responsible for much of mainstream christian doctrine, never met Jesus Christ in person and only had his own claim of an epiphany to give him credence. He had to make a strong case for Christ’s divinity in order to claim his own authority in the early church.

Given that the doctrine of virgin birth is seen by many as evidence of Christ’s divinity, I’ve always thought the statement of James Naylor, an early Quaker on trial for blasphemy was significant:

*“Art thou the only Son of God?” asked the magistrate.
“I am the Son of God,” replied James Nayler, “but I have many brethren.” *

Naylor was subsequently tortured and imprisoned for presumably placing himself on a par with Jesus Christ.

The Unitarians have a standard statement that I think helps to explain their non-christocentric, non-VB views pretty well:
"We teach the religion* of Jesus, not a religion about *Jesus"
ETA: I see that as I was typing someone else touched on the same matter.

Hyam Maccoby’s thesis in The Mythmaker is that Pauline Christianity is substantially a Hellenistic mystery religion, with trappings of that genre such as virgin birth & resurrection, grafted onto a historical failed Jewish Messiah, one Yeshua Barabbas of Natsereth, whose mystic followers believed God had raised Yeshua from the dead & that he would return. The original Jewish movement basically died out in few generations; the mythic Iesous Christos survived, among Gentiles–his religion a fusion of established cultic tropes & pseudo-history.

As I said, a positive attitude is comparison to some., not in comparison to modern culture.

True that.

If the Virgin Birth were not taught in the two Gospels that do teach them, it really would not bear on Christ’s Deity or Divinity, His sinlessness, or His qualification to be our Atonement. I do think that Joseph would get a lot more respect & mention in the Gospels as the man whose seed God’s Son piggybacked on. (Just typing that hurt!) But since the VB is clearly taught there, then to me, it’s almost as important as the doctrines of the Incarnation, the Atonement & the Resurrection.

My recollection is that the VB plays a role in Augustine’s development of the doctrine of original sin, that is that sin is inherited from one’s parents. Christ did not have the taint of original sin because he was not fathered by Joseph, but by the Holy Spirit. And of course this led to the idea that Mary did not pass sin onto Jesus because she herself had been born of “immaculate” conception.

But the Original Sin doctrine, while widely held, is not universally believed in Christianity and in any case does not hinge on VB. I can’t think of any major doctrines that rely on that event.

I think clearly the stories are echoes of previous hero-birth myths. Now a VB believer might say that these earlier myths were “pre-echoes” of the real event that occurred with Jesus’ birth (cf. C.S. Lewis) and other Christians will believe that they are myths that contain spiritual truth without respect to historical accuracy – I tend to fall in the second group. But I can’t think of any doctrine that comes crumbling down if the VB story just disappeared.