What does Luke 1:34 mean?

Mary is an unmarried virgin (Luke 1:26–28) hearing amazing news from the angel Gabriel. His message is that Mary will conceive a Son, to be named Jesus (Luke 1:31). He will be the Messiah: God incarnate and the Savior of the world (Luke 1:32–33; 22:70; 2 Corinthians 1:19; John 3:16). That Mary would bear the very Son of God is incredible—and it leads her to a very natural question.

When Gabriel delivered news of a child to an aging priest and his wife (Luke 1:5–7, 13), his message implied a miracle, but not something unheard of (Genesis 21:1–2). The priest's reaction, unfortunately, was to wonder "if" what the angel said would happen (Luke 1:18). In response, he was temporarily rendered unable to speak (Luke 1:19–20). Mary's reply here is not a question of "if" these things would happen, but "how." She uses the Greek phrase "Pōs estai touto," which literally means "how will this happen?"

Mary's uncertainty is to be expected. The second part of her statement declares "andra ou ginōskō." This literally means "I know no man," a polite but clear reminder that she has never had intercourse. Any number of questions may have been going through her mind, but something about Gabriel's statement seems to have implied this conception was to take place immediately. When this conversation is over, Mary will visit a relative (Luke 1:39), whose unborn child would already recognize the One Mary carried (Luke 1:41–42).

Gabriel will explain that Jesus Christ will be conceived through a miracle of the Holy Spirit (Luke 1:35). This will make Him truly the "Son" of God, as well as free from the inherited sin nature of Adam (Romans 5:12).