Genesis - Chapter 17

As we move ahead in the story of Abraham we will see that Abraham and Isaac will tell the story in advance of God the father and Jesus the son.  That illustration of Jesus life on earth starts here in Chapter 17 when God says that Abraham and Sarah will have a son.  And the comparison with the announcement of the birth of Jesus begins with the response to the impossible news.

Abraham saw that the birth was, humanly speaking, impossible.  He thought to himself, "will a son be born to a man a hundred years old?  Will Sarah bear a child at the age of 90?

Similarly, the announcement of the coming birth of Jesus was even more impossible.  The Angel Gabriel said to Moses (in Luke chapter 1) "you will be with child and give birth to a son, and you are to give him the name Jesus."  And Mary said "How will this be, since I am a virgin?"

The birth of a child to two very old parents was impossible.  The birth of a child to a virgin was impossible.  But as the angel declared "nothing is impossible with God."