He lived during a time of great peril and great change in the world. It was during his time that the Kingdoms of Judah and Samaria first came into conflict with the mighty Assyrians. During his time, the Kingdom of Samaria was actually destroyed by the same Assyrian Empire. The Kingdom of Judah was originally meant to serve as God's way of bringing the light to the nations. During this period, that light is about to be extinguished. Isaiah appears to not only comfort his people, but also to remind them of their calling.
By the time he walked the earth, Judah had indeed fallen far from their calling. After the righteous reigns of Uzziah and Jotham, Ahaz ascended to the throne. Ahaz turned away from God, and committed sins even greater than that of the people of Samaria. He sacrificed his (at the time) only son to pagan idols. He removed the altar of God from the temple, and replaced it with a copy of the Syrian altar in the great temple of Damascus. In his desperation, he swore allegiance to the King of Assyria becoming his vassal, begging the King to bring vengeance upon Samaria. (In a true irony, what he relied upon for salvation ended up nearly becoming his doom.)
This was the time during which Isaiah lived. We know from the introduction that he was the son of Amoz, a man of high nobility. He was born during the reign of Uzziah, and promoted the true worship of Yahweh during his reign. No doubt he had fallen out of favor with the powers that be during the reign of Ahaz. Yet it is during this time that he begins to build his reputation.
What is this reputation? He indicts with great rhetorical power the sins of Judah. The first chapter is full of a seething condemnation of Judah for her sins and hypocrisy. Their hypocrisy if anything makes them worse than the pagans. The pagans knew no better. Judah had the truth, and they had turned their back on it. Here the prophet calls on them to forsake this path in what could be called the summation of Isaiah's entire message:
Wash yourselves; make yourselves clean; remove the evil of your doings from before my eyes; cease to do evil, learn to do good; seek justice, correct oppression, defend the fatherless, plead for the widow.
Come now, let us reason together, says the Lord: though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall become like wool. If you are willing and obedient, you shall eat the good of the land; but if you refuse and rebel, you shall be devoured by the sword; for the mouth of the Lord has spoken.This is a prophecy of restoration. He calls them back not only to the practices of the previous Kings, but to their original calling from Adam, to Abraham and to Moses. They must not only put away the evil they did, but learn to do something in place of it. Many times the people of Judah and her kings would repent of the evil they did, but they continued to do it. There was no real change in their behavior. If anything, the sacrifices they offered were being used as an excuse for loose living. The prophet points out that God does not accept the sacrifices offered unless a real change of heart occurs.
Instead, we must replace our evil with that which is righteous. If we do so, God will bless the land and leave them in security. His message was a great challenge to the people. His next prophesy gives us insight into the fruits of this repentance and conversion. May we likewise repent of our evils and experience true conversion in our hearts and souls.