I also agree that the biblical picture of a human being includes both a physical body, and a spirit. Although many (modern) Christians accept this language, we are not used to asking the question “What of me exists on the physical nature, and what of me exists on the spirit?”
I suggest that the language of the New Testament reflects first century belief that the mind lives on the spiritual side (not the physical). I could make a coherent argument for this, but this comment is not the place for that.
I suggest that New Testament Greek presents the physical side of us, as not including the mind. Emotions seem to be heavily physical, and the New Testament presents the virtue of self-control as the mind controlling the emotions, and keeping them in check. The ancient philosophers also viewed this relationship between the mind, and the physical body.
There is no usage in New Testament Greek, for the meaning of the “flesh” as a summary of what is evil and prone to sin, in us. (!!) This concept seems to be a later concept, used by those who didn’t really understand how the biblical language views the relationship between the physical and the spirit. We get verses that point to the problem of living only according to our physical urges, because in the New Testament Greek, the mind lives on the spiritual side of our being, not the physical side. And our conscience and moral consciousness and our knowledge of God’s will, live on the spiritual side of our being. If we live, bypassing our moral consciousness, then we are living solely “in the flesh.” And this becomes a description of someone who is living as though they had no functional conscience.
Note that the New Testament includes interesting phrases, such as about Jesus, when he was living “in his days in the flesh.”
NIV Hebrews 5:7 During the days of Jesus’ life on earth, he offered up prayers and petitions with fervent cries and tears to the one who could save him from death, and he was heard because of his reverent submission.
RSV Hebrews 5:7 In the days of his flesh, Jesus offered up prayers and supplications, with loud cries and tears, to him who was able to save him from death, and he was heard for his godly fear.
Some of our translations hide this use of “the flesh,” perhaps because some denominations think that “the flesh” must indicate sinful urges.
Some of the classic passages in the NT about our struggle to do what is right, involve this first century language that the mind must impose its will on the physical body. And Paul tells us to get a renewed mind, and be disciplined, to do this. Some of the later theologians sometimes miss that this language is talking about the inherent differences in direction, of the mind and the physical body.
This topic needs a lot more discussion, by Christians.