“But I say, walk by the Spirit, and you will not carry out the desire of the flesh. For the flesh sets its desire against the Spirit, and the Spirit against the flesh; FOR THESE ARE IN OPPOSITION TO ONE ANOTHER, so that you may not (cannot) do the things you please” (Galatians 5:16-17).
There can be several modes of opposition. I might say that the desires of the parent are in opposition to the desires of a child. Is the child indiscriminately evil?
What we see in the Scriptures is an illustration of how the flesh has become disordered. It now produces all sorts of evils from within the human heart. How though does this conflict with the idea that the supernatural must govern the natural?
The flesh must be disciplined by the spirit. Is the flesh evil? What example can we use? Consider fornication, idolatry, gluttony and drunkenness, or calumny. These sins (in the manner of all sins) are perversions of good. Fornication pollutes sexuality, idolatry is wrongful worship, gluttony or drunkeness is misuse of food and drink, calumny destroyes the truth and beauty.
Would you say that sexuality or food or drink are evil? Certainly not. Each pertains to the flesh. Each has become an outlet for our sinful passions because all men have become subject to the law of sin. On the other hand, they are creations of God for the sake of man. The spiritual person can enjoy these within the bounds of God’s law and be free from all sin.
Consider Our Blessed Lord. He was born of the Virgin a true man, the Incarnate Word of God. Incarnate literally means to be born in the flesh. The flesh of Our Lord is not evil though. Christ’s humanity is harmonized perfectly with His deity. His flesh submitted perfectly to His Spirit.
That is the point. Human nature within us has become subject to sinfulness. We are all agreed on this point. However, our humanity is still part of who we are, and this humanity is not intrinsically evil. Jesus Christ Himself took on our humanity. The difference is that His humanity is pure and immaculate, free from the stain of sin. We must be remade in His image by the superabundant riches of His grace.