But you can't deny the confusion, especially when "flesh" means something different than that in 99.99999999% of the times it is used in the Bible.
Generally it is Paul who uses "flesh" as shorthand to refer to the lusts of the flesh and the corruptibility of our own mortal existence and hindrance by sin. A few times outside of St. Paul's letters there is a similar, but not identical usage, usually with a qualifying sense. Which is why context matters--who is doing the writing, what is being said, etc. The Bible isn't magic, and there's no magic decoder ring; the Bible requires actually paying attention and trying to do the effort to exegete, that is, bother to understand what the particular author is trying to say and how they're trying to say it.
But flesh generally just means
flesh. Even when Paul uses it he is largely talking about the fact that while we are in our current state as corruptible, mortal creatures we are bound to the sinfulness of our fallen human disposition right here in our skin-tight selves. So in Paul's usage it's not that being a flesh-solid human being is bad, it's that the tyranny of sin and death is present here in our body, which is why we look forward to the resurrection of the body, and its transformation, redemption, and healing; and indeed the transformation, redemption, and healing of the entirety of all creation, of the whole world.
-CryptoLutheran