The latter part of Isaiah 1 paints a powerful and rather interesting portrait of Israel.

In verses 21-23 God lays out the charges against her. Israel is a prostitute, a murderer, worthless, weak, rebels, thieves, bought & sold, and calloused in their heart and spirit.

Verses 24-25a have God bringing his wrath down on an unfaithful Israel. Raising His fist against her — a metaphor that Isaiah uses constantly.

Verses 25b-27 has God talking about purifying Israel, restoring good judgement & counsellors, a rebuilding her reputation. But this process is bookended by rebellion and destruction.

Verse 28 again Has God visiting wrath upon the rebellious.

Verses 29 & 30 tell of a repentant people who understand the shame of what they have done.

Verse 31 once more has the evil-doer being destroyed, this time by their sin.

I think this is a fantastic flow and way to think about the effects of sin and how God uses them for His purposes of judgement. Paul, in 1 Corinthians 5:5 writes, “[H]and this man over to Satan for the destruction of the flesh, so that his spirit may be saved on the day of the Lord.”

Sin comes to and for all of us. It is rather unavoidable. However, when we are convicted by the Lord or called out by a brother or sister in the faith it is our responsibility to act on that conviction and deal with the sin. If we refuse then Paul says we are to be disfellowshipped. The purpose of this is to let sin run its course. When it does there will be one of two outcomes.

1. Your sin takes a toll on you physically, mentally, spiritually, and/or emotionally (this part is unavoidable) and then you repent, see the truth and return to God. This doesn’t un-do the consequences of sin, but it still puts you in a good place in light of eternity.
2. Your sin takes a toll on you physically, mentally, spiritually, and/or emotionally (I told you, unavoidable) and you do not repent. Your sin continues to destroy you and you are lost in both this world and the next.

Why would God do this? Why cast out the immoral brother or sister? Because when the consequences of sin are minimized, the value of grace is diminished. And if we don’t see how our choices can bring us to ruin, the impetus to change is severely impacted, possibly even erased entirely. But when our sin causes us to lose things that we care about, we suddenly see that we need a way out. And then, when that way out is presented we take and are glad for it. And so this is why God wants our sinful and unrepentant brothers and sisters to be cast out. To fully experience the destruction of their sin. Because when they do, it will put them in the best position to begin to make things right.