Terah is not an enemy — he is the "sane" voice of accommodation. His gods are livelihood and honor, and his advice to his son is exactly the counsel of the crowd:
"The main thing is that a man needs a livelihood. And the god from whom I derive my livelihood — he is God… And if you have grown wiser than all of us, keep your wisdom in your heart… He who guards his mouth and his tongue guards his soul from troubles…" AZR, "Abraham in Ur of the Chaldees" (Collected Writings, vol. 2, Jubilee Committee, 5694/1934), Ben-Yehuda read/28058. (This is exactly the advice of the "rabbits" from "The Diary of Acosta": hold the truth in your heart, just do not speak it.)
Nimrod, whom religion sanctifies as a "son of the gods," sentences Abraham to be burned, and throws him into a pit. But here lies the decisive difference from Acosta: Abraham rejoices:
"And Abram rejoiced in his lot! He had done a good thing… It is good to die for a great and holy idea, for the sanctity of truth… but his soul did not quail." Ibid. (Acosta despises himself and takes his own life; Abraham — his soul "did not quail.")
In the pit Satan appears to Abraham, and in a brilliant theological inversion he presents himself as the conservative, and God as the revolutionary:
"Perhaps it is better that you call me 'Preserver'… The Holy One, blessed be He, builds worlds and destroys them… He is, as it were, a revolutionary — and I am an orthodox who opposes Him. When I see that He is preparing to destroy, I come and hold back His hand and preserve what exists." Ibid.
Satan prophesies to Abraham that his self-sacrifice will beget not "Abrahams" but "Cains, Nimrods," and that even when the idea of the One God spreads, it will be corrupted:
"The brokers of the religions — the priests and the clergy — together with the tyrannical rulers will come in the name of the One God to oppress the laborers, to exploit the poor, and to stir up terrible wars… When the prophets of the ideals succeed in spreading their glorious ideas through self-sacrifice… then the empty and the insolent will hasten to seize the banners from the hands of the men of spirit, and will raise them in their defiled hands and befoul them and mutilate them and make of them instruments for every act of villainy." Ibid. A biting rebuke, through Satan's mouth, on how every revolution and ideal is hijacked. (Compare AZR's criticism of the "schisms" and of the hijacking of movements; see "The Brenner Affair" and "The Labor Movement.")
Abraham's answer is precisely AZR's ethos — not for the sake of the present but for the sake of the perfection to come: "It is not for the people of my generation that I give up my soul… but for the generations to come, to mend the world under the kingdom of the Almighty."
After Satan vanishes, the angel Gabriel appears and delivers AZR's philosophical key — Satan speaks truth, but "his own truth":
"With his own truth he ensnares souls, but it is only his truth, not the truth in its fullness. It is a satanic truth, which leads the weak-sighted astray… There is a moment that all eternities cannot equal — a moment of the soul's perfection and its ascent to the service of the One God, to the good deed… The good deed brings forth good deeds. The mark that the righteous man makes with the good deed will never be erased." Ibid. And with this "the sadness flew from Abram's heart," and he was ready "to mount even the pyre with joy."
The two works are a pair: the same struggle — the lone bearer of truth against the mob/the authority — and two opposite poles. Acosta is truth without the sustaining faith: he breaks, is degraded in his own eyes, and destroys himself. Abraham is truth with faith: the despair that Satan instills (the same despair that defeated Acosta) is vanquished by "the good deed" and "the moment of the soul's perfection." This is the heart of AZR's teaching: the value of the deed in itself (as in Gordon's religion of labor; see "Gordon and the Joy of Labor"), and the "Hasidic" joy as a victory over oblivion.