Human sacrifices are an abomination to both Jews and Christians, yet theologians from both religions have to deal with the account of Abraham offering up Isaac to God.
This story, found in Genesis 22, does not belong to any of the usual sources for Genesis. Some of it looks like it comes from the E Source, since it uses the divine Elohim; other parts look like the J Source, since it uses the divine name Yahweh.
Yet this conflict or ambiguity in source is not a problem; it is a clue to the solution of the problem. This story is a parable; it is not historical. Just as in the unlikely story of Aaron creating golden calves for the people to worship (who can really believe that?), so also this story of Abraham offering up Isaac is a prophetic parable. The different divine names used in this story are an important pointer to its meaning.
Context
Leaving aside the story of Abraham offering up Isaac, the most confronting Biblical story of human sacrifice is one described in 2 Kings 3. Here the kings of Israel, Judah and Edom found themselves on the losing end of a war, when the king of Moab used human sacrifice in order to turn a losing battle in his favour.
We read in Kings that Joram, king of (northern) Israel, began a war against his rebellious vassal, Mesha, king of Moab. Joram was joined in this war by Jehoshaphat, king of Judah and the king of Edom. The initial foray went very well for the Israelites, and Mesha was facing the complete destruction of his country. In desperate straits, Mesha took his first-born son, his designated successor, and sacrificed him on the city wall.
(Some have suggested that Mesha took the first-born son of the king of Edom and sacrificed him. For this reading, one has to assume the writer has been careless with his use of the relevant pronoun.)
The Israelites immediately withdrew, having been (psychologically) defeated by this call upon Chemesh, Moab’s god, to defend the nation in its hour of need. As a result, Mesha, and his nation, survived.
Even more than this, in a wide-ranging victory stele Mesha, king of Moab, claimed that he had successfully resisted the king of Israel. In this stele he claimed the king of Israel had sought to completely end his family’s rule of Moab. Instead of being wiped out by the king of Israel, Mesha claimed he had extended his control into the territory to his north. (This was territory previously assigned to the Israelite tribes of Gad and Reuben.) Furthermore, he claimed that Chemosh, his god, had been victorious over Jahveh, at least in these lands.
Making the situation worse, the famous prophet of Jahveh, Elisha, was with King Jehoshaphat during this battle, and had in fact prophesied the victorious progress of the war against Moab. Yet even Elisha was not able halt the retreat of the Israelites.
A problem needing a solution
There is no record that anyone at the time pointed to the futility of human sacrifice: its potency had been proven in this event. It was a crushing blow to the Israelite religion and worship of the ethical god, Jahveh.
So we should examine the story of Abraham and Isaac to see whether it was a prophetic response to this confronting turn of events, written during the time of King Jehoshaphat of Judah (around 850 BC).
By a careful examination of the use of divine names, we find that Abraham was called upon by Elohim (God or, strictly speaking, the gods) to sacrifice Isaac, but he was stopped by Jahveh.
The lesson of this story is that the gods of the nations may respond to human sacrifice, as Mesha had found, but the Israelite god, Jahveh could not abide the practice.
The prophetic parable finally concludes with Yahweh’s blessing upon Abraham:
Your descendants will take possession of all the cities of their enemies, and through your offspring all nations on earth will be blessed, because you have obeyed me [that is, Jahveh, and not the call of the gods or of Chemosh].
This is an example of a story being invented, with the character of the Patriarch, Abraham, being used to prophetic purposes. The writer’s intention was to show to the people of his own day that Jahveh does not require human sacrifice, and that the nation will be successful without resorting to human sacrifice.
His approach was not entirely successful, for in the reign of Josiah, 200 years later, one of the cults to be removed was that at Topheth, in the Valley of Ben Hinnom (the Gehennah of the New Testament), where human sacrifice had been introduced and was still being carried out.