4. Israel's response 1:21-31

While God's invitation to repent was genuine (vv. 16-20), the nation had so thoroughly departed from Him that repentance was not forthcoming and discipline was inevitable. The prophet bemoaned the depth of Israel's apostasy and announced that the Lord would have to purify His people in the furnace of affliction before they would become what He intended them to be.²⁶

 The depth of Judah's apostasy 1:21-23

Spiritual rot had penetrated even the capital of Israel, and what marked Jerusalem characterized the whole nation. The people, seen in the personification of their capital, who had formerly been devoted to the Lord, had become unfaithful to Him by pursuing other gods. Former glories were now tarnished, and what was once strong was now weak. The leaders of the nation, who formerly had been pure and valuable, were now adulterated and cheap. Rather than serving the people, they served themselves. Idolatry had led to social injustice, as it always does unless checked.

 The announcement of judgment 1:24-26

Isaiah's unusual three-fold description of God as the sovereign (Lord) God of armies (hosts), who is the Mighty God of Israel, boded ill for Judah. The specter of God arising to judge His people for their sins just mentioned is a fearful prospect (cf. Heb. 12:29). God judges sin wherever He finds it, among pagans and among His own people.

"Any facile statement that God always hates the sin but loves the sinner needs to be countered by Isaiah's insistence that those who transgress are my foesand my enemies."²⁷

God would subject His people to fires of adversity but to purify them, not destroy them. Just rulers would emerge and the city would once again enjoy a reputation for righteousness and faithfulness to God. This is the first allusion in Isaiah to a coming judge who will establish justice and create righteous conditions, about whom the prophet revealed much more later. The restoration described here will find fulfillment in the millennial reign of Christ.

 The fate of the wicked 1:27-31

Even though Zion (a poetic synonym for Jerusalem) will experience redemption by God's justice and righteousness (vv. 25-26), the Lord will destroy individuals who continue in their sins and do not repent.²⁸The Israelites had turned to objects of idolatry ("oaks") and places of idolatry ("gardens,"v. 29) and in doing so had forsaken the Lord. God had chosen Israel, but Israel had chosen a tree. It is impossible to turn from the Lord and not turn to an idol. God's people would feel betrayed because of their choice one day (cf. 29:3; 45:7; Ps. 34:5; 119:6). Those who consider themselves strong and self-sufficient, as oaks and gardens, but rely on the creation rather than the Creator to sustain them will wither and dry up (v. 30). Both they and their works will inevitably burn in the fires of God's judgment, like felled trees.