A.B. Simpson emphasizes that the flesh is inherently corrupt and cannot be improved or trained to align with God's law. He illustrates this with the analogy of a wild hawk that cannot be transformed into a gentle dove, highlighting that the carnal mind is in direct opposition to God. The only solution for humanity's sinful nature is not improvement but a complete transformation through the crucifixion of the old self and the reception of divine nature in Christ. Simpson calls for believers to embrace this new identity in Christ rather than attempting to reform the flesh.

The flesh is incurably bad. It is not subject to the law of God, neither indeed can be. It can never be any better. It is no use trying to improve the flesh. We may educate it all we please. We may train it by the most approved methods, we may set before it the brightest examples, we may pipe to it or mourn before it we may treat it with encouragement or severity. But its nature will always be incorrigibly the same. The wild hawk which the little child captures in its infancy and tries to train in the habits of the dove will fasten its cruel beak upon the gentle fingers that caress it, showing the old wild spirit of fear and ferocity. So the flesh is a hawk by nature, and it can never be made a dove. For the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. The only remedy for human nature is to destroy it and receive instead the divine nature. God does not improve man. He crucifies the natural life with Christ and creates the new man in Christ Jesus.