Why do Christians believe in the virgin birth?
Because two independent accounts report it, and neither writer had anything to gain — in that culture it invited the obvious slander, and Matthew records the slander being made. The famous argument about a mistranslation is weaker than it sounds: Jewish translators, two centuries before Christ, chose the Greek word for virgin themselves.
Two of the four Gospels tell the story of Jesus’s birth, and both say the same unlikely thing. Matthew and Luke share almost no material here — different genealogies, different scenes, different people — which is one reason the agreement on this point is interesting.
The mistranslation argument, and why it is weaker than it looks
The standard objection: Isaiah 7:14 says a young woman will conceive. The Hebrew word is almah, which means a young woman of marriageable age. Christians turned it into virgin to manufacture a prophecy.
Here is the difficulty with that story.
The Greek translation of the Hebrew scriptures — the Septuagint — was made by Jewish scholars in Alexandria, beginning around the third century BC. They rendered almah as parthenos, which does mean virgin.
That is two centuries before Jesus was born. Those translators were not Christians, had no interest in a Christian reading, and were not trying to accommodate anything. They looked at the Hebrew and reached for that word.
The reason is not mysterious: in that society an unmarried young woman was assumed to be a virgin, so the two words overlapped in ordinary use. Matthew, writing in Greek, quotes the Greek translation that already existed.
You can still argue about what Isaiah meant in his own century — and there is a real argument, because the passage has an immediate eighth-century context too. What you cannot say is that Christians invented the word.
The reason nobody would fabricate this
Think about what this claim cost in that culture.
An unmarried pregnancy was a catastrophe — social ruin, possible death. Matthew records Joseph’s first instinct, which was to end the engagement quietly, and that is not a detail that flatters anyone.
And the slander followed. Jewish polemic from the second century onwards circulated the accusation that Jesus was illegitimate, and John’s Gospel may record an earlier version of the same jab, when opponents tell Jesus we were not born of fornication.
Fabricating a virgin birth in that world is not adding prestige. It is handing your enemies a weapon they used for centuries.
What it is doing theologically
The claim is not that sex is impure or that Jesus needed to avoid it, which is a common misreading. Christianity does not teach that.
It marks two things at once. That this life did not begin the way every other one does — something arrived rather than only being produced. And that he is genuinely one of us: carried, born, dependent on a mother, subject to everything a body is subject to.
If you wanted a way to say fully God and fully human in a narrative rather than a formula, this is what it would look like.
Objections answered
Isn't this just borrowed from pagan stories of gods fathering children?
Those stories are structurally different — a god takes physical form and has intercourse with a woman, often violently. There is nothing like that here: no consort, no divine seduction, and a Jewish setting in which the idea would be blasphemous. The Gospels describe a creative act, not a coupling.
Mark and John don't mention it. Doesn't that suggest it came later?
Neither of them covers Jesus’s birth at all — Mark begins with the adult ministry and John with a theological prologue. An argument from silence needs the silence to be surprising, and here nothing about their scope makes it so.
Do you have to believe it to be a Christian?
It is in every historic creed, which is as strong a signal as Christianity gives. Some modern theologians have treated it as symbolic; the church as a whole has not, and it is difficult to explain why two independent writers would invent something so costly.
Shared ground, and where traditions differ
All Christians hold
All the traditions confess the virgin birth — it is in the Apostles’ and Nicene Creeds, which Catholics, Orthodox and Protestants all recite.
Roman Catholic
Holds additionally that Mary remained a virgin, and confesses her immaculate conception and assumption.
Eastern Orthodox
Also holds her perpetual virginity and honours her as Theotokos, the God-bearer — a title defined at Ephesus in 431 to protect a claim about Christ.
Protestant
Confesses the virgin birth while generally not holding the later Marian doctrines.
Related questions
Inspired by Got Questions — "Is 'virgin' or 'young woman' the correct translation of Isaiah 7:14?". The argument is theirs; the words here are ours.
Did this answer the question?