I want to get more of the text before us before I comment.
8:1 Therefore there is now no condemnation for those who are in Christ Jesus. 2 For the law of the Spirit of life in Christ Jesus has set you free from the law of sin and of death. 3 For what the Law could not do, weak as it was through the flesh, God [did]: sending His own Son in the likeness of sinful flesh and [as an offering] for sin, He condemned sin in the flesh, 4 so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit.
What is Paul saying here? I underlined the terms "condemnation" and "condemned" because I think these are parallel ideas focused on the final judgment. If a man is "condemned", in the ultimate sense, he will suffer damnation at the judgment. A man doesn't want to be condemned, he wants to avoid this as much as possible. If he is wise, he will seek a way to avoid being condemned at the final judgment.
In this section, Paul is comparing two ways a man might seek to avoid being condemned.
Practicing the moral ethics found in God's law.
A man might find that the moral law of God contains an ethical standard that is worthy of a human being. To live according to such a moral standard, if possible, would be worthy of our consideration and to the degree that one was able to live this way, to that degree, a man would certainly be righteous, and holy and good.
The problem is, however, that living such a life of dedication to God's moral, ethical standard, unfortunately does not free a man of sin and can't keep him from death. The law, in the hands of a sinner, is not going to allow that sinner to rise above his moral/ethical limitations to a level worthy of life.
those who are in Christ Jesus.
The alternative is for a man to find himself in Christ Jesus. Those in Christ Jesus are not condemned to remain in sin, condemned to death, and condemned to suffer the final judgment. What the law could not do is change a man inwardly such that God would accept him and give him life. A man could practice the ethics of God, putting them on as clothing. But a man can't change himself inside, or improve his inwardness. The only one who can do that is God, through the Spirit.
So God sent his son, in the flesh, to condemn sin in the flesh. To "condemn sin", in a similar way as above, is to destroy sin at the final judgment. Rather than the man being condemned to death because of his sin, his sin itself has been condemned to be obliterated so that the man may live. The man couldn't do this himself through his ethical practice, but God could do it for the man who accepts that the innocent man the Jews condemned to die at the hands of the Romans is the one true messiah and son of God.
27 "Now My soul has become troubled; and what shall I say, `Father, save Me from this hour'? But for this purpose I came to this hour. 28 "Father, glorify Your name." Then a voice came out of heaven: "I have both glorified it, and will glorify it again." 29 So the crowd [of people] who stood by and heard it were saying that it had thundered; others were saying, "An angel has spoken to Him." 30 Jesus answered and said, "This voice has not come for My sake, but for your sakes. 31 "Now judgment is upon this world; now the ruler of this world will be cast out.
Jesus knows that he is about to be executed by the Jewish authorities. What they think they are doing is different than what is actually happening. The Jewish authorities, according to their own words, are attempting to save the nation from further Roman oppression by executing a man who claims to be the king of Israel. What is actually happening is that they are putting to death God's choice to be king of Israel, his choice of messiah. Jesus is about to be lifted up from the earth, meaning: he is about to be crucified. This existential moment forces each human being in that time and each of us in our time to face the ultimate question: "Is this man God's messiah or not?"
Jesus says "now judgment is upon this world." What does he mean? I think he is talking about "this world system" and the ruler of that system, "the ruler of this world." In essence, each person living in this world is being forced to make a judgment call of their own. Jesus will ultimately be the ruler of this world and he, himself, is about to be cast out. And each person in this world is going to be required to make a decision. Did the Jewish authorities do the right thing, putting Jesus on the cross, or did they make the biggest mistake in all of history? Do we agree with the Jewish authorities or not? Did Jesus deserve to die or not? Was he the messiah or not? Was he and God united in purpose, character, and intent or not? Was he the son of God or not?
Much more could be said about this world system, which is not only comprised of corrupt governments run by corrupt men and women, but it is permeated by ideas and concepts that are antithetical to God's will for mankind; go for the gusto, obey your thirst, get all you can before you die, do unto others before they do unto you, money can't buy happiness but it can buy everything else, if you are not number one, you are number two, and etc.
But Jesus will return, and when he does, the ruler of the current world system will be cast out, along with his lies, deception, wrong headed ideas, myopic perspective, ambitious selfishness, and etc.
8 "And He, when He comes, will convict the world concerning sin and righteousness and judgment; 9 concerning sin, because they do not believe in Me; 10 and concerning righteousness, because I go to the Father and you no longer see Me; 11 and concerning judgment, because the ruler of this world has been judged.
Here Jesus is talking about what he calls "the Spirit of Truth." The ruler of this world has been judged in at least one significant sense. The ruler of this world is responsible for this world system, which is morally corrupt, lacking in sound judgment, lacking in integrity, crooked, selfish, fearful, suspicious, and full of guile. As such, it was this world system that had the audacity to put the son of God on a cross. They put the man who actually has the right to rule this world, the man who demonstrated love, care, wisdom and obedience to God -- this world system put to death without cause. So then, the Spirit of Truth will make his case for why this world system is flawed and needs to be replaced by the system Jesus Christ will bring.
Colossians 1:5-6, 23
Yes, this world is being changed on a case-by-case basis, one individual at a time. The spirit of truth presents each individual a choice as I described above, and each individual must make his or her own decision. Hear the gospel and believe it, and allow the message to permeate each and every area of life, and walk in the light of it as we wait in hope of his coming.