After reading the wonderful account of Gabriel’s announcement to Mary in Luke 1:26-38, you might wonder the same thing that she did. “How can this be, since I do not know a man?” This is a good question. How could Mary conceive a child without the aid of a man? What Gabriel promised was impossible. Naturally, this would never happen. But Gabriel was not talking about something that would take place naturally. It was something that the God of the impossible would make possible.
“If one is open to the possibility of God entering into history and being able to transcend the ‘laws of nature,’ it is not difficult to believe that the God who raised his Son from the dead and empowered him to do many mighty miracles could have sent him into the world by the miracle of the virgin birth.”
Robert H. Stein, Luke, Nashville: Broadman, 1992, 82.