Romans 8 is best understood after reading the Apostle Paul’s exposition of his own “wretched man” trapped in a “body of death” in Romans 7:14-25. (Read these verses on the site)
There are some who teach from this passage saying that it describes Paul’s life before Christ citing that this description is contrary to his own account or description of true believers in Romans 6 (cf. vv. 2,6,7,11,17,18,22) . However, as we read this passage it is obvious that this is a believer because he desires to obey God’s law and hates his sin. He is humble, recognizing that nothing good dwells in his humanness. He sees sin in himself, but not as all that there is, and he serves Jesus Christ with his mind.