Medical scientist Peter Elwood OBE examines the evidence for the miracle at the heart of the Christmas story 

The virgin birth is just one of many aspects of the uniqueness of Jesus. Everything about him was different. To consider his conception in isolation is therefore not altogether reasonable. On the other hand, because every aspect of his life was different, it would not be unreasonable to expect his origin to be unique as well. There is, however, evidence consistent with his birth to a virgin.

Luke the historian

At the beginning of his record, Luke claims that he had investigated everything to do with Jesus very carefully (Luke 1.1). Recent scholarship has confirmed that Luke is indeed a most careful historian.

He was a doctor and Mary would therefore have found it acceptable to be questioned by him about her conception and pregnancy. Luke also remarks that Mary’s memory was good and that she had kept these events in her mind and had pondered them deeply (Luke 1:19 and 1:51). 

Elizabeth and Zechariah

Luke actually commences his record of Mary’s testimony by introducing the reader to Elizabeth and Zechariah, an elderly, childless and highly religious couple. He tells us that it was a very special time for Zechariah. He was a priest and had been selected to perform some special duties in the temple in Jerusalem. In fact, this couple come over in Luke’s narrative as rather austere and unapproachable – the very last couple to whom a young girl would go if she were in some kind of trouble.

Luke records that Elizabeth became pregnant. Somewhat embarrassing for the woman perhaps! Elizabeth was elderly and her husband was on special temple duties. Her pregnancy was not something she would have been likely to gossip about, and Luke remarks that Elizabeth hid herself for five months (Luke 1:24). Mary, away in the North, will have known nothing of all this.


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Mary’s story

Luke then turns to what Mary had told him. He notes in passing that Elizabeth was then six months pregnant (Luke 1:26). Mary claimed that an angel had visited her and told her that she would become pregnant by a divine agency. Mary’s response was totally natural: “Nonsense! I haven’t known a man sexually” (Luke 1:34). But, Mary told Luke, the angel went on to explain how the pregnancy would commence, and then the angel added the totally irrelevant fact that Elizabeth was six months pregnant (Luke 1:36).

Put yourself in Mary’s shoes. How would you have reacted? The text states that Mary was troubled by the sight of the angel, and I guess that Mary’s concern increased sharply as the angel gave her his message.  And then the angel slipped in the somewhat casual remark about Elizabeth being pregnant (Luke 1:36). What on earth had another woman’s pregnancy to do with what the angel was saying would happen to Mary? 

In fact, in contrast to the distress which is evident in the early part of this narrative, there is a marked calmness in the concluding remark by Mary: “I am the Lord’s servant, let it be as you have said.” (Luke 1:38). Had it suddenly occurred to Mary that the angel had given her one fact that could be checked? See Elizabeth and resolve the doubt – angelic vision or bad dream?

Mary’s journey

Luke records that Mary then left home immediately (“with haste”) and went to see Elizabeth (Luke 1:39). This was quite a remarkable thing for her to do. A young girl, travelling on her own for over 60 miles through territory, some of which will have been hostile to a Jewish traveller. And all to see an elderly childless, highly religious woman, married to a priest!

Surely this is the very last thing Mary would have done had she behaved improperly and feared she might be pregnant. Surely she would have waited at least a month, and probably several. Furthermore, what help and understanding could she have expected from Elizabeth?

On the other hand, if Mary’s story was true, then her journey to see Elizabeth would have been the most sensible thing for her to do – to check the one testable fact that the angel had given her. That journey of Mary was therefore either a bizarre and senseless panic, or it implies a desire to follow through and check the message from the angel.

Just picture Mary on that journey. Driven by distress, she covers more than sixty miles of unknown country. Picture her having to ask directions repeatedly, and having to find lodgings along the way. And then picture her on her arrival with Elizabeth: “Good to see you; and marvellous about your pregnancy…do you know, I’m going to have a baby too!” No way! Mary will have had no such reaction. Rather, she will probably have been overcome with dread at seeing Elizabeth. “So it is true after all…how can I face it?…The neighbours…and what will Joseph say?”

Mary and Elizabeth

Luke records that Mary stayed with Elizabeth for three months (Luke 1:56). Why so long? Wouldn’t a quick glance at Elizabeth have been enough, with perhaps a day or two to recover from her journey? Surely she stayed with Elizabeth in a state of half belief, waiting until her own pregnancy gave further evidence that the angel had spoken truly.

Yet again, why three months? Perhaps she waited until quickening gave unequivocal evidence that there was a child within her. But additional to all that, Mary knew that back home she would have to face gossip and snide remarks from the neighbours. And worse: Joseph, her fiancé, could hardly be expected to believe her story.

Undoubtedly Elizabeth will have had to encourage Mary and perhaps even coax her to return, and the scant record of their conversation together gives evidence that her encouragement will have been based upon the scriptures.


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The timings

Luke’s medical training led him to make notes of the stages of Elizabeth’s pregnancy in terms of the three trimesters. He records that Elizabeth was six months pregnant when the angel visited Mary and he notes that the two women spent three months together (Luke 1.56). Six and three make nine. Then, as now, a pregnancy lasts nine months!

The whole of Elizabeth’s pregnancy is thus accounted for. This validates Mary’s claim that “immediately” after the angel had told her of Elizabeth’s pregnancy, she had gone to see Elizabeth. That is, she had not delayed at home and waited for signs of her own pregnancy before she had undertaken that remarkable journey.

Again, consider the implications. Had Mary’s story been a cover-up for some unfortunate affair, wouldn’t she have waited, at the very least for a month, and probably several, to see if a pregnancy would follow? After all there was a fair chance that it would not. On the other hand, if her story was true, what was more natural than for her to check the one fact the angel had given her within an otherwise incredible message. And again, if Mary’s story was true, then Elizabeth was the only person who could have helped to ease her confusion and distress.


Matthew gives the story from Joseph’s point of view. Matthew had been a tax inspector and he knew the wiles and deceits of men. It is significant therefore that he states that Joseph was “a just man” (Matthew 1:19). Of course Joseph didn’t believe Mary’s story about an angel…women just don’t get pregnant that way! And so it took a visit from an angel to convince him. But notice how Matthew records this: Joseph was considering divorce on the grounds of Mary’s unfaithfulness (Matthew 1:19, 20).

Evidently he was a kindly man, and he decided to divorce her privately so that she would be caused as little distress as possible under the circumstances…but as the thought entered his mind an angel appeared. It is as if the spirit of God would not allow any distrust within the holy family. Therefore, as soon as Joseph had a dishonourable thought about Mary, the angel intervened and cried: “Stop – listen to what is happening!”

One might very reasonably question why there was a second angelic visitation. Surely it would have been far more reasonable, and more economical, for one angel to have seen Mary and Joseph together. This would have avoided the misunderstandings by Joseph and the upset this must have caused both of them. Indeed, had Joseph been in on it all from the start (or before it had all started!) he would undoubtedly have stuck by Mary and would have been an enormous support to her.

No doubt all that is true, but consider what the wider family and the neighbours would have thought! “Some story those two have concocted! What a daft attempt at a cover-up for their misbehaviour.”

Fully man and fully God

The central truth of Christianity is the deity of Jesus, and his origin by virgin conception is totally in keeping with his being God and Man united in one person. Indeed, virgin conception is the only way that a union between God and man could be achieved without compromising the integrity of one, or the other. Jesus’ virgin birth is also consistent with all the other evidence of his deity.

The name for Jesus used by John: ‘The Word’ is of interest here. At one level it carries the idea that ‘the communication’ from God became a man. That is, ‘the message’ from God became a human being. We all know how a letter or phone call can be helpful, but if a matter is of desperate importance, a visit in person communicates in a far, far better way.

But more than that. I am what I am, and you are what you are, because of our genes. Coded into the genes that are within every cell in our body is a vast amount of information, the essence of what makes you you, and me me. Did the second person of the Godhead, ‘the Word’, ‘the communication’ code himself into genetic material, thereby contributing the information that made her offspring the God-man, Jesus Christ? At the same time, the incarnation is still the mystery of all mysteries!

So, a belief in the virgin birth of Jesus is not a ‘blind leap in the dark’. There is evidence in the written records, and while other explanations for Mary’s pregnancy have been suggested, none of these has any ring of truth - and they all imply that Mary was a liar.

In fact, Luke links the involvement of the Holy Spirit within Mary with the deity of her Child: “…because of this He will be called the Son of God” (Luke 1:35).  A rejection of the virgin conception of Jesus would therefore seem to be a rejection of his deity – the very core of Christian truth.

Why virgin birth?

1. The Christian message is all about a relationship between God and men, and the gospel starts with the union of God and man in Jesus Christ. The Christian message has been summed up as the descent of God to man, to enable the ascent of man to God.

2. The Christian gospel is all about ‘mediation’ between a holy God and sinful men. Job cried out in his agony: “Oh that there was someone who could put a hand upon us both and bring us together” (Job 9:33). This is exactly what Jesus Christ can do, being fully God and fully man (Hebrews 3:17).

3. God is infinitely pure and holy, and the Bible says that God cannot so much as look upon sin. Man is sinful and he can neither lift himself up to God, nor cleanse himself and stand before a holy God. The Christian message is that God has come down to man, and in the God-man Jesus, man can be lifted up to God. Our sins can be forgiven and we can be covered by the purity, the righteousness, of Jesus Christ. The union between the sinner and Christ is therefore spoken of as being “in Christ”.

“Jesus, Thy blood and righteousness, My beauty are, my glorious dress:

Midst flaming worlds, in these arrayed,

With joy shall I lift up my head.”

(Jesus, thy Blood and Righteousness by von Zinzendorf)

4. A key element in salvation is redemption, a concept which is taken from the slave market. If a person had lost his freedom, or his inheritance, these could be bought back - but only a blood relative could redeem. In fact, the old word ‘kinsman’ means, in Hebrew, ‘one who can redeem’. To be our redeemer, Jesus had first to become one with us, our kinsman.

5. The Christian has a high priest who knows and understands, not just because as God he is all-knowing, but also, because he was here (Hebrews 2:17,18). He learned through the things he suffered (Hebrews 5:8) and so he fitted himself to be merciful and understanding, able to show compassion on the weak and needy. (Hebrews 5:1-6).

6. Jesus himself warned that he would conduct the final judgement of men, and when speaking of judgement, he referred to himself as: “The Son of Man” (John 5:27). That is, by being man, by living on this Earth and by facing all the temptations and difficulties we face, Jesus prepared himself to be our judge. Because he is God, he has the right to judge, and because he is man, he is fitted to judge. There will be no fooling him on that day, and no saying that he does not understand! He knows and he understands - he was here!


Peter Elwood OBE qualified in medicine in 1954 at Queens’ University, Belfast. After ten years in hospital and general practice he was offered a job in a medical research unit in Cardiff. Peter has spent 60 years working as an epidemiologist and though he retired almost 30 years ago, he is still working and publishing. His current interest is in aspirin as a possible additional treatment for cancer. In 2013 Peter was awarded OBE for ‘Services to Health’.