In this series we are following the repeated themes in the book of Genesis.  In this message, Pastor Andrew observes that God's promise to give Abraham a large family (a central component of Genesis) is actually an impossible promise, because Abraham's wife Sarah, and 2 other key characters in the book of Genesis, are all unable to have children!  Following this theme through the book of Genesis invites us to look at our expectations of God.  Is anything too hard for Him?