"Do not be afraid, Mary; you have found favor with God. You will be with child ..." (Luke 1:30)
No matter how troubled Mary was, her heart had been cultivated by faith, and she responded to the news with composure, dignity, and faith. She did not scream or fall on her face. She simply asked the angel a question: “How will this be … since I am a virgin?” (v. 34).
She asked with expectancy. “How will God do this, with me being a virgin and all?” It is not a question of doubt. It is a question rooted in faith. Mary immediately believed Gabriel. She did not laugh as Sarah did when she overheard the conversation between her husband and the Lord that she in her old age would bear a son. When confronted with the miraculous, Mary asked "how will".
Unbeknownst to Mary, this same angel had visited her relative Zechariah and brought him astonishing, impossible news. When Gabriel told Zechariah that he and Elizabeth in their old age would have a son, an amazing son, Zechariah asked, “How can this be?” (v. 18, author’s paraphrase). Not how will. How can. The difference exposed his heart. He did not believe the angel, and it did not go well for him. Mary was blessed by the angel above all women. Zechariah was struck dumb.
Mary asked, “How will?” She knew that if God says something—anything—we can believe him. God is true. He is trustworthy. Jesus is a man of his Word.