Passages for 1.5.20: Genesis 16-18; Mark 6.
Remember the exchange Abraham had with God in Genesis 17? Here are several verses to refresh your memory:
And God said to Abraham, “As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name. I will bless her, and moreover, I will give you a son by her. I will bless her, and she shall become nations; kings of peoples shall come from her.” Then Abraham fell on his face and laughed and said to himself, “Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child?” And Abraham said to God, “Oh that Ishmael might live before you!” God said, “No, but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will establish my covenant with him as an everlasting covenant for his offspring after him. As for Ishmael, I have heard you; behold, I have blessed him and will make him fruitful and multiply him greatly. He shall father twelve princes, and I will make him into a great nation. But I will establish my covenant with Isaac, whom Sarah shall bear to you at this time next year.”
Abraham = 100. Sarah = 90. Yeah, they’re old! And yet, God promises to give them a child, not through Sarah’s servant Hagar but through Sarah. In 17:1, God refers to Himself as “God Almighty” translated from “El Shaddai.” This name of God describes a God who makes things happen by means of His majestic power and might. Can God do what He promised to Abraham and Sarah? Of course! And He did!
Kent Hughes, in his commentary on Genesis, writes this concerning the “why” of God invoking His name of “El Shaddai”:
“I am able to fulfill the awesome hopes that I have set before you of a people and a land. There is no need to let go of the promise because of your old age. There is no need to succumb to passive desperation. There is no need to scale down the promise to match your puny thoughts – no need to resort to fleshly expedience – no need of trying to fulfill the promise in any second-rate way. Everything – all of your life, all your future – lies in this: I am God Almighty!”