"The flesh" describes the natural man. God has no program to change the flesh. Rather He brings in something new: "and that which is born of the Spirit is spirit" (John 3:6). A new struggle is brought to our attention. It is no longer the new nature or the believer striving for mastery over sin in the body; it is the Holy Spirit striving against the old nature. The little boy coming home from school was beaten up by a big bully. He was on the bottom, and the big bully was pounding him very heavily. Then he looked up from his defeated position on the bottom, and saw his big brother coming. The big brother took care of the bully while the little fellow crawled up on a stump and rubbed his bruises. The believer has the Holy Spirit to deal with the flesh, that big bully. I learned a long time ago that I can't overcome it. So I have to turn it over to Somebody who can. The Holy Spirit indwells believers. He wants to do that for us, and He can! - James Vernon McGee