Monotheism in Isaiah
The monotheistic confession in Isa 40–48 is best understood against the historical context of Israel’s political and religious crisis situation in the final years of Neo-Babylonian rule. According to Deutero-Isaiah, Yhwh is unique and incomparable because he alone truly predicts the “future” (Isa 41:22–29)—currently the triumph of Cyrus—which will lead to Israel’s liberation from Babylonian captivity (Isa 45). This prediction is directed against the Babylonian deities’ claim to possess the power of destiny and the future, predominantly against Bel-Marduk, to whom both Nabonidus and his opponents appeal in their various political assertions regarding Cyrus. According to the Babylonian conviction, Bel-Marduk has the universal divine power, who, on the one hand, directs the course of the stars and thus determines the astral omens and, on the other hand, directs the course of history (cf. Cyrus Cylinder). As an antithesis, however, Deutero-Isaiah proclaims Yhwh as the sovereign divine creator and leader of the courses of the stars in heaven as well as the course of history on earth (Isa 45:12–13). Moreover, the conflict between Nabonidus and the Marduk priesthood over the question of the highest divine power (Sîn versus Marduk) may have had a kind of “catalytic” function in Deutero-Isaiah’s formulation of the monotheistic confession.