There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit. For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death. (Romans 8:1-2)
"Not guilty; let him go free" - what would those words mean to you if you were on death row? The fact is that the whole human race is on death row, justly condemned for repeatedly breaking God's holy law. Without Jesus we would have no hope at all. But thank God! He has declared us not guilty and has offered us freedom from sin and power to do His will.
The Greek word for "therefore" does not draw a formal conclusion, but an informal inference, from Romans 7:25. In contrast with the preceding vivid description of sinfulness, Paul depicts the freedom of living in the Spirit. There is no condemnation when you are "In Christ", we are no longer under the sentence of the law, but empowered by the Spirit to live for Christ.
The Spirit of life is the Holy Spirit. He was present at the creation of the world (Genesis 1:2), and He is the power behind the rebirth of every Christian. He gives us the power we need to live the Christian life (Acts 1:8).
Who is the Holy Spirit? God is three persons in one - the Father, the Son, and the Holy Spirit. God became a man in Jesus so that Jesus could die for our sins. Jesus rose from the dead to offer salvation to all people through spiritual renewal and rebirth. When Jesus ascended into heaven, His physical presence left the earth, but He promised to send the Holy Spirit so that His spiritual presence would still be among mankind (Luke 24:49). The Holy Spirit first became available to all believers at Pentecost (Acts 2:1-4). Whereas in Old Testament days the Holy Spirit empowered specific individuals for specific purposes, now all believers have the power of the Holy Spirit available to them (Romans 14:16-28; Romans 8:9; 1 Corinthians 12:13; 2 Corinthians 1:22).
For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh, that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit. (Romans 8:3-4)
Jesus gave Himself as a sacrifice ("sin offering") for our sins. In Old Testament times, animal sacrifices were continually offered at the temple. The sacrifices showed the Israelites the seriousness of sin: blood had to be shed before sins could be pardoned (Leviticus 17:11). But animal blood could not really remove sins (Hebrews 10:4). The sacrifices could only point to Jesus' sacrifice, which paid the penalty for all sins.
The law could pronounce judgment on sin, but the law could not do anything about sin itself. It had no power to put sin to death in a person’s life. God accomplished what the law could not do by sending His own Son. Jesus came in the likeness of sinful flesh: Jesus, as God, took on our human nature, a nature that was susceptible to temptation. Although He was tempted, He never gave in. He never sinned.
The purpose of the coming of Christ was that the law might be fulfilled. The believer gains the righteous standard of the law—love (Romans 13:8–10)—not by means of the law but by being in Christ and walking according to the Spirit.
In Romans 1:18 and Romans 3:20, Paul develops an argument that no one can claim by their own efforts or merits to be good in God's sight - not the masses, not the Romans, not even the Jews. All people everywhere deserve God's condemnation for their sin. Thank you Lord Jesus for dying on the cross for my sins so I can stand before a righteous and Holy God. Amen.
References: NKJV Holy Bible, Life Application Bible (NIV), the Nelson Study Bible.