“How can this be since I do not know man?” (Lk. 1:34)
Mary has only one question for the angel Gabriel. And it’s a question that provides a beautiful window into Our Lady’s unique spiritual life, but one we might overlook if we don’t read the Annunciation account carefully:
Mary says to the angel, “How can this be since I do not know man?” (Lk. 1:34). 
Two important facts will help us better appreciate the significance of Mary’s question. First, at this moment in the story we know that Mary is a virgin betrothed to Joseph, meaning that she is at the first stage of marriage. She is truly married to Joseph but not yet living with him, for she has not arrived at the second stage of marriage known as the “coming together,” when husband and wife typically would begin to live in the same house and consummate the marriage.
Second, Mary has been told by Gabriel that at some time in the future she will bear a son who will be the royal Son of David, the Messiah-King. Notice the future tense: “You will conceive in your womb and bear a son” (Lk. 1:31, emphasis added). So far, Gabriel gives no indication that the conception will take place right now or in the immediate future. In fact, the timetable is quite open-ended. Without giving any time specification, the angel simply informs Mary that she will conceive this child at some time in the future.
Now consider this: If Mary were just an ordinary Jewish betrothed woman—planning on consummating her marriage once she reached the coming-together stage—when would she expect such a pregnancy to take place? In other words, if a betrothed woman in the first century was informed by a prophet that she was going to have a child at some time in the future, when would that woman expect such a pregnancy to begin? Presumably, sometime after betrothal—after the coming together, when sexual intercourse was permitted. Spoken to an ordinary betrothed woman, such an announcement about conceiving a child would naturally point to her future married life, after consummation.
Vow of Virginity?
In this light, Mary’s question seems rather peculiar: “How can this be since I do not know man?” If Mary is planning on consummating her marriage with Joseph in the near future, the answer to her question should be obvious. While she does not right now have the power to conceive a child (since she doesn’t yet “know” man sexually), if Mary intends to know Joseph after the coming together, then she evidently will be able to have a child at that point. Therefore, if Mary is planning on consummating her marriage with Joseph, her question — “How can this be since I do not know man?” — simply does not make sense.
This is why some Church Fathers and Doctors of the Church have seen in Mary’s question an indication that she was not intending to consummate her marriage. According to this perspective, Mary raises her question because she has made a decision to remain a virgin throughout her life. This view, advanced by theologians such as St. Augustine, St. Thomas Aquinas, and St. Bonaventure (and even Martin Luther), explains Mary’s question not as one of doubt, but one that seeks clarification as to how she can conceive a child if she has committed herself to the Lord in virginity.
One of the earliest proponents of this position, St. Gregory of Nyssa, points out how Mary’s question makes no sense on the lips of a betrothed woman—unless she had made some prior commitment to lifelong virginity. After all, why would she ask this question if she was intending to have sexual relations with Joseph?
- For if Joseph had taken her to be his wife, for the purpose of having children, why would she have wondered at the announcement of maternity, since she herself would have accepted becoming a mother according to the Law of nature?
- But just as it was necessary to guard the body consecrated to God as an untouched and holy offering, for this same reason, she states, even if you are an angel come down from heaven and even if this phenomenon is beyond man’s abilities, yet it is impossible for me to know man. How shall I become a mother without [knowing] man? For though I consider Joseph to be my husband, still I do not know man. 
John Paul II drew a similar conclusion, teaching that long before the Annunciation, Mary’s heart was inclined toward virginity as the Holy Spirit inspired in her a desire for full communion with God as His faithful bride.
- Neither the Gospels nor any other New Testament writings tell us when Mary decided to remain a virgin. However, it is clearly apparent from her question to the angel at the time of the annunciation that she had come to a very firm decision. Mary did not hesitate to express her desire to preserve her virginity even in view of the proposed motherhood, showing that her intention had matured over a long period. 
I Do Not Smoke
According to John Paul II, when Mary’s question is seen in this light, her statement about not knowing man further indicates her intention to remain a virgin. He notes how Mary’s expression about not “knowing” man is in the present tense, which “reveals the permanence and continuity” of her virginal state. Mary says she does not know man in the sense that she does not intend to know man.
To use an analogy: If someone said to me, “You will die of lung cancer in the future,” and I replied, “How can this be since I do not smoke?” my response would not simply describe a present circumstance (“I don’t happen to be smoking right now”). Rather, it would indicate a long-term intention on my part to avoid smoking (“Smoking is not something I ever intend to do”). Analogously, Mary’s expression “I do not know man” — when seen in the wider context of the Annunciation account—further suggests her commitment to remain a virgin for the rest of her life.
Then Why Would Mary Marry?
While Mary’s commitment to virginity makes the most sense out of her question, two objections commonly arise. First, some object that Jews in the first century did not hold up virginity as a religious ideal. The Old Testament highlights how being fruitful and multiplying is a blessing and notes how dying childless is perceived as something to bewail.
However, one may respond by explaining that while a commitment to virginity was not common in ancient Judaism, it was not unheard of. The prophet Jeremiah was called by God to remain celibate (see Jer. 16:1). John the Baptist, St. Paul, and Jesus Himself remained celibate. Many members of a Jewish sect known as the Essenes practiced celibacy. There is even evidence of at least some Jewish women remaining virgins by their own decision. Therefore, while virginity was by no means a widespread religious ideal, remaining a virgin in order to serve God was not completely unheard of in the first-century Jewish world in which Mary lived. If these others willingly lived lifelong virginity, there’s no reason to exclude the possibility of Mary doing so, too.
A second question often raised is, “Why would Mary accept betrothal to Joseph if she intended to remain a virgin?” Diverse explanations have been given for this unique marriage. Perhaps since remaining a single woman was not as socially feasible in the ancient world of Judaism as it is today, marriage would have provided economic stability and social protection for Mary. Perhaps the marriage was arranged. Perhaps marriage would free Mary from other men seeking her hand in marriage and thus protect her vow. Perhaps God led Mary to marriage because in His providence, He wanted to protect her reputation for the future when she would conceive by the Holy Spirit. John Paul II pondered this question, too, and offered his own suggestion:
We can wonder why she would accept betrothal, since she had the intention of remaining a virgin forever… It may be presumed that at the time of their betrothal there was an understanding between Joseph and Mary about the plan to live as a virgin. Moreover, the Holy Spirit, who had inspired Mary to choose virginity in view of the mystery of the Incarnation and who wanted the latter to come about in a family setting suited to the child’s growth, was quite able to instill in Joseph the ideal of virginity as well. 
The Power of the Most High
When Gabriel answers Mary’s question, he provides an even fuller picture of this extraordinary conception and the child she will bear. Gabriel said, “The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore the child to be born will be called holy, the Son of God” (Lk. 1:35).
These words reveal the divine origins of this child. Mary learns that she will not conceive this child through natural sexual relations, but by the Holy Spirit. And this is why the child will be called the “Son of God”—this is not merely in reference to His function as the Messiah (as the Davidic kings were described as God’s sons), but even more fundamentally, in connection with His conception by God’s Holy Spirit.
Another fascinating piece of Gabriel’s message to Mary is how he tells her, “The power of the Most High will overshadow you” (Lk. 1:35). The verb for “overshadow” in Greek (episkiazein) is the same word used in the ancient Greek translation of the Old Testament to describe the cloud of God’s presence overshadowing the tabernacle at Mount Sinai (Ex. 40:35; Num. 9:18, 22), and for that same cloud of God’s glory that overshadowed Israel as the people left Sinai (Num. 10:34, 36) and that overshadowed Mount Zion for the Jewish feasts (Is. 4:5). Therefore, when Gabriel says, “The power of the Most High will overshadow [episkiasei] you,” he is indicating that this same power of God now overshadows the new tabernacle, the new vessel of God’s holy presence — the Blessed Virgin Mary, who will bear in her womb God made man.
Mary’s Fiat: A Lover’s Vow
We don’t know a lot about what Mary was thinking when she heard all this from Gabriel. But put yourself in her shoes. In the midst of her ordinary day, an angel suddenly appears. That alone would be quite startling. Next, this angel greets her, saying, “The Lord is with you” and “you have found favor with God” — two Old Testament expressions which signal that Mary is being called to an important and difficult mission on behalf of God’s people. Then, the angel tells her that she will have a child and that this child will be the long-awaited Messiah-King, the one who would fulfill all the prophecies about the Davidic kingdom. And if that’s not enough, Gabriel also informs her that she will conceive this child in a way that has never occurred before — not by sexual relations, but by the power of the Holy Spirit. Finally, on top of all this, Gabriel announces that her child will just happen to be the Son of God Himself.
That’s an awful lot to take in from one short conversation with an angel!
The only hint we receive about what Mary was experiencing in those pivotal moments before the Incarnation is her response: “I am the handmaid of the Lord; let it be to me according to your word” (Lk. 1:38). John Paul II and others have pointed out how Mary’s “let it be to me” indicates not a passive acceptance of God’s will, but an active, loving embrace of it. Mary does not just submit to God’s plan; she longs to fulfill it, “making it her own.”  Mary responds like a lover who, once she sees what is on her beloved’s heart, ardently seeks to fulfill his desires. May we become more like Mary, approaching God’s will not merely as a servant, but as a lover who seeks satisfy the desires of God’s heart.
Footnotes Author’s translation from the Greek.  St. Gregory of Nyssa, On the Holy Generation of Christ, PG 46, 1140 C–1141 A, as cited in L. Gambero, Mary and the Fathers of the Church (San Francisco: Ignatius Press, 1999), p. 157.  John Paul II, General Audience, August 7, 1996, as cited in John Paul II, Theotokos (Boston: Pauline Books and Media, 2000), p. 124.  John Paul II, General Audience, August 21, 1996, as cited in John Paul II, Theotokos (Boston: Pauline Books and Media, 2000), pp. 127–28.  John Paul II, General Audience, September 4, 1996, as cited in John Paul II, Theotokos (Boston: Pauline Books and Media, 2000), p. 135.
Reprinted with permission from the May/June 2007 issue of Lay Witness magazine. © 2007 Catholics United for the Faith / www.cuf.org/Laywitness/index.asp
Check out Dr. Sri’s bible study, Mary: A Biblical Walk with the Blessed Mother, available from Ascension Press.