One must note that "flesh," like some words in Scripture, has more than one meaning. "Flesh," as used in the verses you quote, is speaking of that sinful nature, of living in state of continually following our sinful desires. But, physically, we are obviously living in bodies of flesh. If you were physically dead, we wouldn't be having this discussion.We are not in the flesh ( we are quickened together/resurrected with Christ in us.)..
Romans 7:5 For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death.
6 But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter.
Romans 8:8 So then they that are in the flesh cannot please God.
9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
10 And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness.
11 But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
Your view appears to be becoming more Gnostic, much like that of the OP.