“Thus says the Lord:
“Keep justice, and do righteousness
for soon my salvation will come,
and my righteousness be revealed” v. 1
Isaiah is an amazing book. I hope you can see by are time already spent in it why it has such a great theological impact on the New Testament.
As a side note, the word “Theology” comes from two Greek words: “Theos” meaning ‘God”, and “Logos” meaning “Word.” So Christian theology is simply an attempt to understand God as He is revealed in the Bible. When you hear some talk about the theology of a book, section, or passage of the Bible, they are asking what is what we are reading trying to teach us or reveal to us about God. And a Theologian, is simply a person who invests time and wrestles with discovering and discerning these revelations from God. In our house churches when after reading a bible passage and we ask each other; “What does this passage teach us about God?” “What does it teach us about his relationship to people? We are actually looking into the theology of that passage. So above when I said, “why it (Isaiah) has such a great theological impact on the New Testament.” I am saying that the Jews had an understanding of God and the “Servant” from their reading of Isaiah. This understanding of God and the Servant, was the “lens” through which the Jews, as well as the apostles, Paul, and James experienced Jesus, and God through Jesus, and it comes out in their Gospels and letters. It also comes out in the teachings of Jesus. So it is important to understand this “lens” they are looking through, to understand some of what they experienced and wrote. Just like understanding the “lens” though which someone sees God: Church of Christ, Methodist, Roman Catholic, Jehovah Witness, Holiness, Baptist, Morman..ect will give you an insight into how they experience and understand God.
After reading the first 55 chapters, and the closing truths of chapter 55, you would think, Why add anything more? What could possibly be added to the promise of return to their land and the forgiveness of their sins, both by the pure grace of God? What theological understanding did Isaiah feel needed yet to be shared in the last 10 chapters? The central idea of Isaiah I believe is the necessity in the living out of God’s righteousness, given to us by grace as explained in the previous chapters, and the inability of failure of people to do it. Isaiah also looks at the question, What qualifies a person to be among God’s elect? Is it a matter of grace by reason of ones birthright or is it a matter of works?
This whole book flows out of chapter 6 when a “man of unclean lips” sees something of the holy glory of God, receives a fiery cleansing from God, then steps out is trust and obedience to proclaim to Israel the message that there is only One Holy God. In chapters 56-66, Isaiah looks at what happens when “people of unclean lips” get a vision of God, receive grace, forgiveness, and deliverance, and are now enabled to live as God lives.
The grace of God in delivering from uncleanness is not for the servants, those in the churches enjoyment but in order for the word to get out to all that there is only One Holy God, one righteous Savior and that the whole world needs to know him. The grace of God is free, but those who receive it are called to live it out and all its implications in their life, And there is the problem. It has been demonstrated throughout history over and over people cannot live out their God’s character. Are those who have been delivered from their sins by the grace of God simply doomed to ruin God’s name over and over again? Does the salvation of God involve something more? Is there power in God to enable one to live out the covenant to God in faithfulness-not a power one has gained in oneseslf, but a power that one can constantly draw from God? The answer Isaiah gives in these last 10 chapters is a resounding, YES!! Those who choose to make the Servant an offering for sin may also find in him the power to live the lives of the servants of God.
56:1-8 makes it shockingly clear those who are those servants especially pleasing to God. It is not those who are in the blood line of Abraham. Those who maintain the basic cultic way and religion that define the people. His people are anyone who reveals a loving relationship with him by living his life. It is not to whom or where you were born, but character that marks a servant of God.