Mary inquired how she could have a son when she was a virgin. She may have been concerned that Gabriel, who looks like a man, wanted to be the father. Perhaps she wondered if Joseph could be the father and how this would affect her relationship with Joseph.
Mary wasn’t doubting God’s ability. Rather, who would be the father? Mary had a willing heart.
Interestingly, Mary asked only about this and not about the other things the angel said. Why? Perhaps because almost all Jews of those days knew a lot about the Messiah. She was asking for God’s direction in fulfilling this prophecy. She had a good spirit of inquiry. It is acceptable and important to have discernment in what others are asking and saying.
