“… what the Torah, weakened by the flesh, could not do.” So Romans 8:3. What could the Torah not do?
The “just requirement of the Torah” does not refer to human behavior of doing the Torah but to the final verdict the Torah will make regarding a person. The verdict so desired is “life.” The Torah, Paul says, could not pronounce life because it was weakened by the flesh. Its promise to bring life is frustrated by the flesh.

But, God did bring life by sending the Son and by the Spirit.
Here’s this thesis: “God condemned sin in the flesh of Jesus, so that the life the law offered could rightly be given to those led by the Spirit” (578).
Wright insists that the death of Jesus was more than a legal exchange, but a genuine condemnation of sin (and the flesh?). Sin is done away. It is done away with in Christ, who represented all of Israel and his whole people. Jesus is the “sin-offering” for unwitting sins (Lev 5:7-8; 6:25) and therefore deals with the problem of the “I” in Romans 7.