This was Mary's response to the news that she was carrying the Savior of the world, the Son of God, Jesus. Can you imagine the fear and uncertainty that Mary was feeling? Here she was a virgin and yet she was carrying a child. She was unmarried and going to have a baby. On top of that, this wasn't just any child... but the Son of God. In the midst of the fear of being addressed by an angel and finding out the incredible news, this was her response. What an example to all of us. When God shows us His will (or even if He doesn't) we can respond, "be it unto me according to Thy word and will, Lord."