The Reason For God's Righteous Judgment on Sin

Isaiah 1:21 (ESV) How the faithful city has become a whore, she who was full of justice! Righteousness lodged in her, but now murderers.

One thing we are going to see in the prophets is the clear evidence of a godless culture. And here's the thing. Most of us think godliness is boring and keeps us from the fun or enjoyment we want. But it's far more sinister than that. It corrupts not only us, but the people around us and the culture those people (and we) make up. 

Isaiah describes the condition of Jerusalem. He calls her a whore. He reminds us of her former days of justice and righteousness but now it's a place of crime (murder) and disregard for humanity. 

In a godless culture, the economic system is unfair:

Isaiah 1:23 (ESV) Your princes are rebels and companions of thieves. Everyone loves a bribe and runs after gifts. They do not bring justice to the fatherless, and the widow’s cause does not come to them.

Imagine leaders who make friends with thieves! Imagine the injustice rampant in a city where bribes run the show. Many people from many nations can testify to such cultures. And who gets hurt? The powerless - the orphan and widow. 

Most important, God makes himself an enemy of such cultures. 

Isaiah 1:24 (ESV) Therefore the Lord declares, the LORD of hosts, the Mighty One of Israel: “Ah, I will get relief from my enemies and avenge myself on my foes.

As such, God promises to act. 

Isaiah 1:25 (ESV) I will turn my hand against you and will smelt away your dross as with lye and remove all your alloy.

Notice God's plan of attack is to remove the sin and stain of the culture. And then He promises to restore her from the top down. 

Isaiah 1:26 (ESV) And I will restore your judges as at the first, and your counselors as at the beginning. Afterward you shall be called the city of righteousness, the faithful city.”

The prophets are wonderful in this way. Yes, there are warnings and stern rebukes. But they are always intended for good. God wants sin out of our culture and our lives because He knows it hurts people and destroys cities. 

Then the hint of the Gospel:

Isaiah 1:27 (ESV) Zion shall be redeemed by justice, and those in her who repent, by righteousness.

What justice redeems the holy city? God's perfect justice of Christ on the cross bearing the sins of those who repent and seek him. The righteous lamb of God will become sin for us.

Romans 3:23–26 (ESV) for all have sinned and fall short of the glory of God, 24 and are justified by his grace as a gift, through the redemption that is in Christ Jesus, 25 whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. 26 It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus.

Isaiah opens with a warning of judgment and a promise of salvation. You can't come to one without considering the other. Before God, we deserve death and punishment, but in Christ, we are perfectly saved from it. He makes us His own so that we can live for Him.