The NIV 365-Day Devotional Reading PlanCampione

How could God be so unforgiving?

Because the nation of Judah was so unrepentant. Because God is holy, he cannot ignore sin. As it was, God had shown incredible patience toward them, even though they had repeatedly broken their covenant with him.

Through the prophets God had repeatedly invited the people to restore their relationship with him. But the people had rejected his prophets and his message. Even the annihilation of the northern kingdom of Israel (722 BC) had failed to convince the people of Judah to repent.

Though God may appear to have been unforgiving, in reality Isaiah was only declaring what the people had already decided: they would not repent; they would not change their sinful way of life; they would not seek God. The result? They would not be forgiven but would pay the price for their sinful ways.

Taken from NIV Quest Study Bible