God is both The judge and The Savior. This means that God has a plan to make all things right in the end, and that a necessary part of that process is declaring what is not yet right. This is the message of Isaiah the prophet. The judgment of God declares what is broken; the promise of God is to heal.
https://www.insight.org/resources/bible/the-major-prophets/isaiah
Isaiah is widely regarded as one of the greatest prophets of the Bible. His name means “YHWH (the LORD) is salvation.” He lived in Jerusalem and the prophecies God gave him were directed toward Israel, Judah and other nations. Jewish tradition says he was of royal descent, and he may have been a cousin to King Uzziah. This may have given him access to the kings of Judah in Jerusalem.
The biblical account in chapter 1, verse 1 of the book he authored says he received visions from God during the reigns of four kings of Judah—Uzziah, Jotham, Ahaz and Hezekiah. The time covered is from the end of King Uzziah’s reign (Isaiah 6:1) to the Assyrian King Sennacherib’s siege of Jerusalem. It was at least a 40-year ministry during the last half of the eighth century B.C.
What did Isaiah do?
Isaiah was married to a prophetess (Isaiah 8:3). They had two sons whose names had prophetic meanings. They were Shear-Jashub (Isaiah 7:3, meaning “a remnant shall return”) and Maher-Shalal-Hash-Baz (Isaiah 8:1-4, meaning “speed the spoil, hasten the booty”).
Isaiah and his family would be for “signs and wonders in Israel” (Isaiah 8:18). His prophecies are still “signs and wonders” for us today.
https://lifehopeandtruth.com/prophecy/prophets/prophets-of-the-bible/isaiah-the-prophet/
Why major? Isaiah spoke about Jesus’ saving the world:
Isaiah 53:5
Isaiah 53 is probably the most famous example claimed by Christians to be a messianic prophecy fulfilled by Jesus. It speaks of one known as the “suffering servant,” who suffers because of the sins of others. Jesus is said to fulfill this prophecy through his death on the cross.
We serve an unchanging God. God Experienced ‘time’ as a continuum. What is now has already been. Man does not change
God will hear and answer them—
Even the one who sits enthroned from of old— Selah.
With whom there is no change,
And who do not fear God. Psalm 55:19
“But You are the same,
And Your years will not come to an end. Psalm 102:27
“For I, the Lord, do not change; therefore you, O sons of Jacob, are not consumed.” Malachi 3:6
Jesus Christ is the same yesterday and today and forever. Hebrews 13:8
Every good thing given and every perfect gift is from above, coming down from the Father of lights, with whom there is no variation or shifting shadow. James 1:17
“And to Him was given dominion,
Glory and a Kingdom,
That all the peoples, nations and men of every language
Might serve Him.
His dominion is an everlasting dominion
Which will not pass away;
And His Kingdom is one
Which will not be destroyed. Daniel 7:14
https://bible.knowing-jesus.com/topics/God-Is-Unchanging
God Speaks, His Word changes not. BE STRONG and of good courage; do not be afraid, nor be dismayed, for the LORD your GOD is with you wherever you go. He changes not; He is the same yesterday, today, and forever. He is your Helper, and He will never leave you nor forsake you.
https://everydayservant.com/top-13-bible-verses-god-never-changes/