When God enters a situation that situation is transformed – and always for the better. This first chapter in Isaiah gives us a great (summary) overview of the entire book. We learn that God is displeased with His people because they are unholy, wicked and far removed from His will, His purposes and His character. However, through God’s forgiveness, His grace and His mercy Judah will be transformed and will become an instrument of righteousness. God’s people become an instrument whereby God accomplishes His purposes through them.

Verse 18: “’Come, please, let us argue together,’ says the Lord. ‘Since your sins are like scarlet, as snow they shall be. Though they are red like crimson, as wool they shall be.’”

Come, please: A strong request made in very polite terms. God wants to do a work of grace and mercy in the lives of His people. He wants to forgive them. He beseeches them, in a very polite way, to receive His kindness.

Argue: Reason. A word of argument. Biblically, this kind of argument is talking about arriving at the proper or right conclusion to a matter (arriving at truth). It is not a word of rejection or contention.

Your sins are like scarlet, as snow they shall be: This is a picture of the transformation or change that is going to take place. That which is unholy can become holy. That which is stained with sin (as the term ‘scarlet’ conveys) can be made pure (white like snow). God is
the One who does this work in us. We cannot do it for ourselves. 

Verse 19: “If you intensely desire and if you will listen, the good of the land you will eat.”

Listen: This change begins because people are listening to God, hearing His revelation. We listen to God through His Word. It is when we hear the Word of God that transformation can take place in our lives (Romans 10:17).

Note: In this verse God is revealing an important truth about who He is and how He behaves. Although the people have been rebellious, God, who is rich in mercy and grace, has extended an invitation of mercy to them. Those who intensely desire this transformation, that only God can bring about, and those who listen and are obedient are not only forgiven, are not only changed, but they also become partakers of the goodness of God and of His creation.

Verse 20: “’But if you refuse and rebel, the sword will devour.’ For the mouth of the Lord has spoken.”

If you refuse and rebel, the sword will devour…: God’s forgiveness, mercy, partaking of His goodness etc is conditional on our response.
The mouth of the Lord has spoken: God is serious about this. God is willing to forgive. He has invited us to repent. He is capable of cleansing us. He is generous and He loves us. We, however, need, with great desire, to be willing to respond to Him.

Verse 21: “How has this faithful city become a harlot? I have filled her with justice; Righteousness dwells in her, But now murderers.”

Note: In this verse God reminds the people of their current state. This is His perspective, how He sees them. It is important for us to understand sin from God’s perspective. If we do not understand that we are sinners in need of mercy, then we are not candidates for
salvation. This doesn’t mean that we need to be experts and understand everything about sin, but we do need to know what kind of behaviour God considers sinful and what He considers righteous. 

Before salvation we can agree that certain behaviours are sinful, but it is only after salvation, when the Holy Spirit comes to dwell in us, that He gives us the strength to turn away from it.

Faithful city: Referring to Jerusalem.

Harlot: The core of harlotry, in the prophets, is the issue of idolatry. Even in the city of Jerusalem there was much idolatry.

But now murderers: Instead of justice and righteousness, which God had placed in that city, there was murderous activity. Murderers were welcome there.