Whom Shall I Send?

Andrew Grills

3 November 2020


The book of Isaiah is the greatest of the prophets and among the most significant books in the whole Old Testament. Isaiah is the most quoted Old Testament book in the New Testament with 66 specific quotations and many more allusions. It is also the only Old Testament book quoted or alluded to in every New Testament writing. It is not too much to say that its theology and its prophecies are key foundations on which the New Testament is built.

The book itself is lofty in style, soaring in grandeur and beautiful in its language. Written fully or in part by Isaiah of Jerusalem in the latter half of the 8th century BC it is collection of oracles, sermons, pronouncements, reflections and narratives. The content is described as the vision of Isaiah and it spans the long years of Isaiah’s ministry in Jerusalem and Judah under multiple kings who at times enjoyed great prosperity and yet also faced the rising power of the Assyrian Empire.

Tradition claims that Isaiah was an aristocrat, even in the direct royal line and his language, style and content certainly suggest a high level of learning and education. Unlike other prophets (e.g Jeremiah) Isaiah himself is usually invisible in the book with his material mostly coming directly from God, although he does play an important political role at times in the book, specifically during the years of King Hezekiah’s reign. Tradition records that his long prophetic ministry finally came to an end during the evil reign of Manasseh (Hezekiah’s son) when, refusing to be silent, he was sawn in two.


Like many of the Prophets Isaiah is a challenging book to read, interpret and to preach. The vision he is given speaks directly into his own time and situation, with its brokenness, rebellion and sin. Into this context Isaiah speaks judgement, comfort and hope, but then (often in the same passage) stretches away into the future soaring above the brokenness and squalor to highlight eventual resolution in God and his Messiah.

The overwhelming theme of the book is the holiness of God. The adjective holy is used more frequently in Isaiah than the whole of the Old Testament put together (33 times in Isaiah versus 26 in the rest of the Old Testament). The power, beauty and glorious holiness of the sovereign God, and the corresponding squalor of sin are painted in vivid imagery throughout. This is how Isaiah’s call began in chapter 6 with his great vision of the Lord ‘High and lifted up’ with the seraphs chanting Holy and the corresponding awareness of his own sin which is removed by the divine coal placed in his mouth. Isaiah speaks clearly to his world which had a real problem with God’s holiness and therefore couldn’t grasp the realty of their sin. Our world still struggles with both these things which alone makes this book enduringly helpful.

There are many other rich theological themes such as the motif of the city of Jerusalem/Zion which finds it theological groundwork here in Isaiah and continues in the rest of scripture culminating in the New Jerusalem of Revelation. Other themes include the judgment and grace of God, the practical intersection we find of faith and politics and indeed in faith and work as God spoke into the politics and society of his day.

But Isaiah is also a Messianic book. Despite its wide variety in material and style and setting the themes of the Messiah runs like a vein of precious gold through the book, disappearing at times for long periods, but remerging again. But rather than a single unified image of the coming Messiah, the Bible commentator J. Alec Motyer (The Prophecy of Isaiah, 1993) describes this as 3 distinct portraits, showing different angels and perspectives. He breaks these messianic portraits up as:

The king - chapters 1-37
The servant - chapters 38-55
The announced conqueror - chapters 56-66

There is broad agreement on this division among evangelical commentators. As such the book of Isaiah provides us with the most comprehensive prophetic picture of Jesus Christ in the entire Old Testament. It includes the full scope of His life: the announcement of His coming (Isaiah 40:3–5), His virgin birth (7:14), His proclamation of the good news (61:1), His sacrificial death (52:13–53:12), and His return to claim His own (60:2–3). Because of these and many other texts it is no wonder that Isiah is the most prominent OT book in the NT.


The size of the book, long running arguments about authorship in some seminaries, its theological depth and its difficulty in interpretation mean that it is actually relatively rarely preached on and often put into the ‘too hard’ basket.

There are several valid ways we could have chosen to preach through this book. We could preach through it chapter by chapter over a number of years. We could look at Isaiah thematically, or even just cherry pick some of the most famous passages.

We have opted to use the Messianic theme of Isaiah as our organising principle. We will follow its thread through all three building blocks of Isaiah as they are revealed in the canonical shape of the book. We will do this in two distinct sermon series. The first will focus on the prophecies of the birth and the ministry of the coming King. The second (to be done some time in the future) will focus on the messianic prophecies of the suffering Servant and the final Conqueror leading into Easter.


This title comes from directly from Isaiah 6 where Isaiah is confronted by a vision of God on his throne. This title speaks to several themes which the series will explore.

First, it highlights the need. Someone needs to be sent to convey the good news and fulfil the mission of a Holy God to sinful people. In the first instance this of course is Isaiah himself. But the Messianic theme in the book makes it very clear that Isaiah is not the final solution. Another, far greater one, will need to be sent.

Andrew Grills

Andrew is the Lead Pastor of City on a Hill Geelong. He has spent most of his life as an officer in the Australian Army. Graduating with the Sword of Honour from the Australian Defence Force Academy, he served in Infantry and Intelligence, including operations in East Timor with the commandos. He holds a postgraduate degree in International Relations from Oxford University and an MDiv from Ridley College. Andrew later became an Army Chaplain at the Australian Recruit Training Centre at Kapooka, before leaving the full time Army in 2013 to plant City on a Hill Geelong. Andrew has been married to his beautiful wife Danna for over 20 years and has five young children. He loves the ocean, traveling, camping, playing with his kids (including attending their innumerable sporting matches), and reading military history.