What does Romans 8:4 mean?

Paul is continuing to explain how it can be that God will never condemn those who are in Christ Jesus (Romans 8:1). In the previous verse, he showed that God acted to save us from the law of sin and death. We were stuck. We all sinned, and we were all condemned to die.

To change this, God sent His Son Jesus to earth as a man who had no sin Himself (Hebrews 4:15). He was sent for sin, to receive God's condemnation of death for sin once for all in His own sinless body (2 Corinthians 5:21).

Now Paul explains that this was necessary in order to fulfill the righteous requirements of the law. After all, the law of Moses was given by God. It is His law. He fulfilled the requirements of His law by paying out on His own Son the death we had earned with our sin so that justice was done. Sin was paid for.

This was not a universal action for all people as a group. This death for sin was personal. It was Jesus' death for our sin. The requirement of the law is fulfilled in us, individually. Our personal sin has been paid for by Jesus' personal death.

Now, Paul concludes, we are the people who no longer walk—or live—by the flesh. We are not self-propelled. Christians walk and live by the Spirit. This does not mean that Christians never sin in our flesh (1 John 1:9–10). It means that we don't live that way (1 John 3:4–6). All of the life in us comes from God by His Spirit. To the extent that we live at all, we live in the Spirit's power.