Authorship of Isaiah

Read the book of Isaiah and you’ll quickly realise that it is not a biography. The focus is on the message, not the man who proclaimed it.

We do know about his calling, though: a close encounter with the majesty, holiness and mercy of God left Isaiah a changed man.

And we know about the time at which he lived. In his day, the twelve Jewish tribes were tragically divided into a northern and a southern kingdom, Israel and Judah. To make matters worse, the budding superpower of the day, Assyria, was expanding westward and posing a threat to both.

When the kingdom of Israel formed an alliance with its eastern neighbour, Aram, King Ahaz of Judah felt threatened and asked Assyria for military help in return for paying tributes. Isaiah, the prophet, condemned Ahaz’s strategy. 

Assyria ended up conquering Israel and reached the gates of Jerusalem in 701 BC. Unlike his father Ahaz, King Hezekiah followed Isaiah’s advice and stood up to the aggressor. The siege failed, and the mighty Assyrian army withdrew. 

In other words, Isaiah prophesied during an era of national trauma. The kingdom of Israel had ceased to exist, and Judah was at risk of suffering the same fate. But Isaiah didn’t stop there. 

Chapter 39 predicts that another empire, Babylon, will rise and achieve what Assyria failed to do. Jerusalem will be conquered, and those who survive will be forced into exile. Turn the page to chapter 40 and we’ve leapt from the eighth to the sixth century BC. The prophecy of the previous chapter has been fulfilled and, desperate to return to Jerusalem, the Jewish people are weeping at the rivers of Babylon. Five chapters later, we read yet another prophecy. One day, God will deliver them. Persia will end Babylonian supremacy and the Persian king will let God’s people go. 

Did Isaiah (the writer of chapters 1 to 39) address events well beyond his own lifetime or are chapters 40 to 66 not by the same person? To complicate matters further, chapters 56 to 66 move from the Babylonian exile to the period after the exile and include prophecies about the end of time. Most Bible scholars, therefore, speak of First, Second and Third Isaiah.

They point to the time gap between the Assyrian and Babylonian eras, stylistic differences between the first 39 chapters and the rest, as well as the vision in the later chapters, which speak of Israel being a light to the nations and God’s salvation reaching beyond his chosen people to everyone on the planet. 

Does it matter whether Part Two and Part Three were penned by Isaiah or by anonymous, prophetic writers? As we observed a moment ago, the Bible doesn’t care so much about Isaiah the man as about the oracles of God. Whoever was moved by the Spirit to write them, to Christians the latter chapters are among the most meaningful:

Chapter 53 speaks about the Suffering Servant, whom Christians identify with Jesus: 

But he was wounded for our transgressions, 
crushed for our iniquities; 
upon him was the punishment that made us whole, 
and by his bruises we are healed. (Isaiah 53.5)

Chapter 56 extends God’s offer of salvation beyond Israel to the whole world:

And the foreigners who join themselves to the Lord, 
to minister to him, to love the name of the Lord,
and to be his servants, 
all who keep the sabbath, and do not profane it, 
and hold fast my covenant – 
these I will bring to my holy mountain, 
and make them joyful in my house of prayer; 
their burnt-offerings and their sacrifices 
will be accepted on my altar; 
for my house shall be called a house of prayer 
for all peoples. (Isaiah 56.6–7)

The penultimate chapter of Isaiah introduces a vision which is reflected in the penultimate chapter of the book of Revelation:

For I am about to create new heavens 
and a new earth; 
the former things shall not be remembered 
or come to mind. (Isaiah 65.17)

Isaiah’s focus on judgement, redemption and hope, as well as his global, eternal vision, inspired the early Christians. No wonder this ancient prophet is one of the New Testament writers’ favourite sources; apart from the Psalms, there is no book in the Hebrew Bible they quote more often than Isaiah

All Bible quotations are from the NRSV.