The contradiction between the spirit, the body.

From the moment we receive the Holy Spirit into our hearts, we can no longer live “after the flesh.”
Do you know the Holy Spirit? St. Paul still teaches, “Those who live as he wills the flesh, seek only the things of the flesh; but those who live as the flesh wills the Spirit, after spiritual things. The efforts of men of the flesh lead to death and the efforts of spiritual men to life and peace. Therefore, the strivings of carnal men stand at enmity with God, for they are not subject to the law of God, yea nor can they be. Those who live to their flesh cannot please, God. But you do not live after the flesh, but according to the Spirit, if indeed the Spirit dwells in you. God” (Am 8:5-9).
The habit of pitting the spirit against the flesh is an ancient one, though it is not always clear how this is to be understood. The origin of this language seems to be found in the Indian sages. In Greek Platonic philosophy, it was understood as a radical distinction between the material body and the immaterial soul, which was therefore considered spiritual. This implies the moral necessity to renounce material values, to reduce to the smallest degree the needs of the body, and to follow the path of asceticism. Exhortations (exhortations), taken from Greek literature, were often repeated by the Church Fathers. But we must be careful to understand their proper meaning in a Christian setting. The word “spirit” in the new meaning is reserved for the Holy Spirit, and only the person we can call “spiritual” in whom the Holy Spirit works Holy Spirit. Then the term “body” also takes on a new meaning. It does not only mean the material element of our person and therefore created by God as good.

 One spirit with the Lord’s “flesh” according to St. Paul refers to all centrifugal, sinful inclinations that oppose the work of the Holy Spirit both in the inner man and in the world. This resistance to the Spirit, a consequence of sin, is not only in the body but above all in the soul. Hence, we are not surprised at the statement of Origin, which says that the souls of sinners are “carnal” and that the first “carnal” is the devil himself, even though he has nobody. It is important to realize the meaning of this terminology to understand the texts of Scripture and the Fathers properly, and to avoid the misunderstanding that Christianity seems to be the enemy of the human body. On the contrary, even the body must participate in the ideal of “progressive virtualization” of the human person.