However, it is the revelation of scripture that is being interpreted and debated. For example, James claims that the only human aspect of Christ is a physical body that descended from Adam and so Christ is not humanity as humanity involves more than a human body. For examples, angels take upon bodily appearance of men and demons possess human bodies but neither become man simply because they possess human bodies.
For example, James defines God to be "spirit" and thus the "spirit" in Jesus was not human but divine.
The problem is that the damage incurred upon humanity was by Adam a full and complete human being. The Messiah is said to be the "Second Adam" and therefore must be a partaker of humanity as much as the unfallen first Adam in order to redeem us. Something less than full humanity cannot redeem humanity. For example, angels are also spirit creatures but God did not send an angel to indwell a body to redeem us. Christ has to be fully man in spirit, soul and body to redeem man who is spirit soul and body. Hence, Christ was more than a human body indwelt by Spirit God the Son.
Furthermore, the nature of the redemption could only be completed by God as the righteousness required is "the righteousness of God" not found in fallen man nor can be ever produced by fallen man. The penalty for sin is "eternal" which can never be satisfied by a finite creature because only an infinite being can satisfy an eternal penalty, one who encompasses eternity.
Hence, the Messiah must be fully man and fully God without confounding either.
Do you not find it a bit interesting that the orthodox Christian view (you depart slightly from it) was developed over four centuries after Christ in order to address the differences that had arisen within the Catholic church?
In other words, neither Scripture nor the early church believed that Jesus had two natures. The Chalcedonian Creed does not actually detail these two natures as much as it denounces the “hybrid” position that had arisen. They concluded that these “two natures” were indivisible, and inseparable (which denounces one heresy) and that they were also “unchangeable” and without mixture or confusion (denouncing another heresy). In other words, the Chalcedonian formula was not scripture but was a reaction to defend against false doctrine.
I already told you that I believe Christ had “one nature” in terms of being human and divine without division. To me, this means one divine-human nature (Jesus did not “use” different natures, but took on flesh). I believe nature ontological in terms of the will, not ability or attribute (not those qualities that can be set aside or not exercised…like omniscience, omnipotence, etc.). Instead I see the divine nature as perfectly faithful, righteous, holy, enduring, love, etc. I cannot see a change in nature here. But I conceded to using “two natures” in that you are adamant to define God’s nature through His non-communicable attributes.
So yes, what is being discussed and debated is not Scripture itself but our philosophies, theories, and interpretations of how things may have happened in the mind of God. I will stand on my belief here, but not so dogmatically as to denounce fifteen centuries (in terms of PST) or four centuries (in terms of the "two natures") as lacking biblical understanding.