At this point in the story it would seem that Isaac was the offspring we were looking for. Is he the one that will crush the serpent’s head? Is he the one to shed blood? Is he the one that brings adoption for slaves?
It starts off with the appearance that he may be because the Lord asks Abraham to do something that seems crazy:
“He said, “Take your son, your only son Isaac, whom you love, and go to the land of Moriah, and offer him there as a burnt offering on one of the mountains of which I shall tell you.” (Genesis 22:2 )
Here the son is to be offered as a sacrifice, blood is to be shed. And Abraham obediently prepares. Abraham knows the Lord and trusts in him, he trusts that either the Lord will raise his son to life or will provide another sacrifice. Abraham trusts that a lamb will be the sacrifice:
Abraham said, “God will provide for himself the lamb for a burnt offering, my son.”(Genesis 22:8 )
Just as Abraham was about to perform the sacrifice, the Lord interrupts and stops Abraham:
“He said, “Do not lay your hand on the boy or do anything to him, for now I know that you fear God, seeing you have not withheld your son, your only son, from me.” And Abraham lifted up his eyes and looked, and behold, behind him was a ram, caught in a thicket by his horns. And Abraham went and took the ram and offered it up as a burnt offering instead of his son.”
(Genesis 22:12-13 )
This son wasn’t sacrificed but the Lord provided a sacrifice in his place. But the sacrifice wasn’t that of lamb as Abraham thought, it was a ram. And so Abraham calls this mountain “The Lord will provide”. And here in Moriah is the same place that the temple is built-in 2 Chronicles 3:1.
And so we wait for the lamb to be sacrificed. We know that Isaac isn’t the offspring that will crush the serpent’s head and so we wait for the Lord to provide the offspring that will be a sacrifice for us all.
Christmas is about God providing a Son to be sacrificed, a lamb to take away the sins of the world.