In Isaiah chapters 40-48 there are several different titles for God, for example Creator, Redeemer, Savior, The First and the Last, King of Israel. After considering these titles I came to the conclusion that God in these chapters was referring to Jesus Christ and not God the Father because they all match titles given to Christ and never specify the father. What evidences are there of Jehovah being Jesus Christ in these verses, and what evidences are there against it? Answers from believers in the trinity, or not are both welcome.
The answer to your question is a qualified yes. If we are to accept that all Scripture is inspired by God, then we can logically deduce that Jesus gave these predictions to Isaiah to write. Whether or not those exact words are the utterances of a pre-incarnate Jesus or not is not worth arguing in that they are so accurate that whether they came from Isaiah or from Jesus they are predictive of him.
Isaiah gave the most and the most accurate predictions of Christ of all the Prophets, however; much of his writings were to bolster the spirits of those exiles to Babylon, and even those prophesies concerning Christ were given to show that God would not abandon his people.
This excerpt is from the commentary known as the ‘Treasury of Scriptural knowledge.’
Isaiah has, with singular propriety, been denominated the Evangelical Prophet, on account of the number and variety of his prophecies concerning the advent and character, the ministry and preaching, the sufferings and death, and the extensive and permanent kingdom of the Messiah. So explicit and determinate are his predictions, as well as so numerous, that he seems to speak rather of things past than of events yet future; and he may be rather called an evangelist than a prophet.
In addition the following will help in understanding Isaiah’s prophesies when compared to the Gospel accounts and come from the same source:
(Compare Isa_7:14 with Mat_1:18-23, and Luk_1:27-35; see Isa_6:1-13; Isa_9:6; Isa_35:4; Isa_40:5, Isa_40:9, Isa_40:19; Isa_42:6-8; compare Isa_61:1, with Luk_4:18; see Isa_62:11; Isa_63:1-4); his miracles (Isa_35:5, Isa_35:6); his peculiar character and virtues (Isa_11:2, Isa_11:3; Isa_40:11; Isa_43:1-3); his rejection (Compare Isa_6:9-12 with Mar_13:14; see Isa_7:14, Isa_7:15; Isa_53:3); his sufferings for our sins (Isa_50:6; Isa_53:4-11); his death and burial (Isa_53:8, Isa_53:9); his victory over death (Isa_25:8; Isa_53:10, Isa_53:12); his final glory (Isa_49:7, Isa_49:22, 33; Isa_52:13-15; Isa_53:4, Isa_53:5); and the establishment, increase, and perfection of his kingdom (Isa_2:2-4; Isa_9:2, Isa_9:7; Isa_11:4-10; Isa_16:5; Isa_29:18-24; Isa_32:1; Isa_40:4, Isa_40:5; Isa_42:4; Isa_46:13; Isa_49:9-13; Isa_51:3-6; Isa_53:6-10; Isa_55:1-3; Isa_59:16-21; 60; Isa_61:1-5; Isa_65:25); each specifically pointed out, and pourtrayed with the most striking and discriminating characters. It is impossible, indeed, to reflect on these, and on the whole chain of his illustrious prophecies, and not be sensible that they furnish the most incontestable evidence in support of Christianity.
I have highlighted those verses which are contained in your question, but It is well worth taking the time to study Isaiah in relation to the Gospels.
From a Catholic Perspective, no one can understand scripture unless the LORD opens their mind to understand it, and ordinarily through the ones to whom the understanding was first imparted. Thus the Ethiopian Eunuch had Philip and St. Paul had Anani′as and other disciples at Damascus.
Therefore it is in the New Testament we come to understand who the Creator, the Redeemer [cf. the first 7 on the list] , the Savior [cf. those from Ch 40-48], the First and the Last (those from Ch 40-48), and the King of Israel [cf. Is 44:6] is.
- In Is 41:4, the LORD says, 'the LORD, the first, and with the last; I am He.'
- Jesus as Creator: all things were made through him and whatever the Father does, Jesus does likewise.
- In the New Testament Jesus is the Redeemer and Savior, we have shown above that he is the Creator and LORD, and in Isaiah above, the Creator and LORD is also Redeemer and Savior.
- King of Israel: Of the testimonies in New Testament, Nathan′a-el's and those of the people [cf. Jesus’ Triumphal Entry into Jerusalem] stand out.
- The first and last of Revelation is Jesus.
Therefore you are not wrong in concluding that God in these chapters was referring to Jesus Christ.
Please see this answer of mine where I opened by saying:
Following the example of St. Justin Martyr (c.100 – 165 AD) who identified the Angel of the Lord with the Logos, theophanies in the Old Testament are said to have been the preincarnate appearances of Christ.
Gerald A. Larue says in Old Testament Life and Literature chapter 18 that the Book of Isaiah can be divided into three distinct sections, which were probably originally either two or three separate books. This is now a consensus among biblical scholars. Chapters 1 to 39 were written during the late eighth and early seventh centuries BCE by Isaiah, son of Amoz, apart from numerous additions from a later period. For ease of reference, Isaiah is often referred to as First Isaiah, or proto-Isaiah. Chapters 40 to 55 were written by a prophet living in exile during the latter part of the Babylonian Exile. This author is referred to as Second Isaiah or Deutero-Isaiah.
Isaiah chapters 40-48 can therefore be read in the context of an author who actually lived during the events he describes, rather than an earlier author writing about future events. This does not mean that Second Isaiah did not make prophecies about his future, but this knowledge helps us to understand if and when he is prophesying, and what those prophecies may mean.
The writing of Second Isaiah begins with words of comfort, then a passage made famous when copied by the author of Matthew’s Gospel (40:3): “The voice of him that crieth in the wilderness, Prepare ye the way of the Lord, make straight in the desert a highway for our God.” Chapter 40 is lively and optimistic, praising God.
God speaks through chapter 41, taking credit for the victories of Cyrus (41:2:“the righteous man from the east”; 41:25: “from the east I summon him by name.”) against the Babylonians, then assuring the Jews of his support. In 44:28-45:2, God speaks of Cyrus, the Persian conqueror who has liberated the Jews: “ That saith of Cyrus, He is my shepherd, and shall perform all my pleasure: even saying to Jerusalem, Thou shalt be built; and to the temple, Thy foundation shall be laid. Thus saith the LORD to his anointed, to Cyrus, whose right hand I have holden, to subdue nations before him; and I will loose the loins of kings, to open before him the two leaved gates; and the gates shall not be shut; I will go before thee, and make the crooked places straight: I will break in pieces the gates of brass, and cut in sunder the bars of iron.”
Through the voice of God, this author shows contempt for Babylon, in chapter 47. Then exultation in 48:20: "Go forth from Babylon, flee from Chaldea! With shouts of joy proclaim this, make it known; Publish it to the ends of the earth, and say, "The LORD has redeemed his servant Jacob."
Divine references in the passage
The God of Israel (41:17;45:3,15;48:1) is unambiguously God the Father. He is identified in 48:2 as 'Lord of hosts', a title the New Testament never uses for Jesus. Isaiah 44:6 equates 'Lord of hosts' with other titles: LORD, Israel's King and redeemer. I think a good case can be made that all divine references in Isaiah chapters 40-48 are to God the father.
Isaiah 42:1-4 is the first of the ‘Servant Songs’, in which God promises to choose a servant who will teach his true way to the nations. Bruce Feiler says in Where God Was Born, page 314, that in some verses, the servant appears to be a person, in others a group, in some a real figure and in others imaginary. He says the only time the ‘servant’ is named, the reference is to Israel. Some attempts to explain the servant in 42:1-4 are that this is a reference to Second Isaiah himself, to a now unknown leader of the Jews or even to the people of Israel. However, many Christians see the Servant Songs as prophecies of Jesus.
To correctly answer this question the titles need sorted into the two logical descriptors of God. Does the title apply to that of Existence (The Father) or does the title apply to that of Understanding (The Son of Existence). Though as a quick answer, because all understanding does exist. All that is understood comes from Existence. Since Jesus is the Father as well. Jesus indeed is speaking in Isaiah 40-48, in fact no speech occurs that is not of God the Father (otherwise it does not exist: Simple Right!).
For titles that apply to that of Existence (The Father)
Since the Laws of Existence are the Laws of Physics, titles that portray the absolute perfection of the Laws of Opposite Equal Reaction. Can be attributed to that of the Father. Also titles that focus on God's "Oneness".
For titles that apply to Understanding (The Producer of Love)
Titles that portray Communication, and Love. Can be attributed to that of the Son.
Titles for the Father
Existence: (Defined as LORD because everyone must follow the physical laws of Motion) (Isaiah 40:2)
The Breath of Existence (Otherwise known as the Holy Spirit) (Isaiah 40:13)
The Holy One (With references to the One this speaks of the All of Existence) (Isaiah 40:25)
I am Existence the First and the Last (Isaiah 41:4)
The everlasting God, the Lord, The Creator of the ends of the earth (Isaiah 40:28)
the Holy One of Israel (Isaiah 41:14)
the Hand of Existence (This could be an arguable choice considering Jesus being the body ^^, yet he is all the same God right! Anyways..) (Isaiah 41:20)
King of Jacob (Selected since the Lord at this time was the Opposite and Equal Reactions, as explained through Moses) (Isaiah 41:21)
The Creator of Israel, your King (Isaiah 43:15)
Lord of hosts (Isaiah 44:6)
the Rock (Isaiah 44:8)
He who formed you from the womb (Isaiah 44:24)
the God of Israel (Isaiah 45:3)
Elohim: (Defined as God, however I find this word to mean objects, an object is part of Existence, this is why it is plural, meaning objects) (Isaiah 40:1)
Titles for the Son
Comfort: Although not used as a title for the text it is a title. (Isaiah 40:1)
The Breath of Existence (Otherwise known as the Holy Spirit) (Isaiah 40:2)
Redeemer (For the answer to the problems of the knowledge of error, is faith in understanding) (Isaiah 41:14)
My Elect One (Isaiah 42:1)
your Savior (Isaiah 43:3)