Isaiah seems to have been quoted by New Testament writers as applying to Jesus' second coming, but Isaiah wouldn't have been writing about Jesus. To him, God is One and "there is none else". I suspect that if anyone suggested that God had a son or that there were three persons within Him, Isaiah would have thought that blasphemy. He could not have been writing about Christ.
In Romans, Paul has probably quoted Isaiah in his epistle, and adapted it to show that Christ is the judge of mankind, and that men should leave that judgement to Him. This is something that is quite common in scriptures, and the way many interpret them even now. They re-interpret scripture to fit current beliefs that the original author or prophet could not have meant. An example of this is in Revelation, when John identifies the great dragon (derived by the Jews from Babylonian myth) with the serpent in Eden and Satan; if you read the Genesis story and the Book of Job, you will see that these were not identified with each other and weren't intended to be; the stories were re-interpreted to fit the beliefs current in the 1st century.
In Philippians, Paul has claimed that Jesus is the Lord, again reading back into Isaiah something that Isaiah couldn't have meant.
John, in Revelation 1:7, makes the second coming of Christ unmissable, and he talks about Christ being seen even by those who pierced him, implying that Christ's second coming was expected within the lifetimes of those living when the letters of Revelation were written. The rest of Revelation talks about expectations of the time, like the imminent fall of Rome (the whore of Babylon) and of the Beast (Emperor Nero); another prophecy that didn't materialise in the expected time frame.
So the expectation of the second coming of Christ was in the late 1st century or early 2nd century. But this didn't happen, and believers have tried to re-interpret when this would happen - for example, the Millerites. Some even try to interpret that the Fiirst World War was foretold by Revelation, and that we are now in the end times; no doubt, this will again be re-interpreted when iit doesn't happen.
To me, the scripture refers to expectations held at the time they were written. Reading changed beliefs back into older scripture seems contrived.
Source(s):
Isaiah 45:22-23, Look unto me, and be ye saved, all the ends of the earth: for I am God, and there is none else. I have sworn by myself, the word is gone out of my mouth in righteousness, and shall not return, That unto me every knee shall bow, every tongue shall swear.
Romans 14:10-12, But why dost thou judge thy brother? or why dost thou set at nought thy brother? for we shall all stand before the judgment seat of Christ. For it is written, As I live, saith the Lord, every knee shall bow to me, and every tongue shall confess to God. So then every one of us shall give account of himself to God.
Philippians 2:9-11, Wherefore God also hath highly exalted him, and given him a name which is above every name: that at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.
Revelation 1:7, Look, he is coming with the clouds, and every eye will see him, even those who pierced him; and all the peoples of the earth will mourn because of him. So shall it be! Amen.