In other passages also he is accustomed to put the natural condition instead of the works that are done therein, as when he says, that "they who are in the flesh cannot please God." Now, when shall we be able to please God except whilst we are in this flesh? There is, I imagine, no other time wherein a man can work.
For although he says that "in his flesh dwelleth no good thing; " although he affirms that "they who are in the flesh cannot please God," because "the flesh lusteth against the Spirit; " yet in these and similar assertions which he makes, it is not the substance of the flesh, but its actions, which are censured.
For when he actually declares that "they who are in the flesh cannot please God," he immediately recalls the statement from an heretical sense to a sound one, by adding, "But ye are not in the flesh, but in the Spirit." Now, by denying them to be in the flesh who yet obviously were in the flesh, he showed that they were not living amidst the works of the flesh, and therefore that they who could not please God were not those who were in the flesh, but only those who were living after the flesh; whereas they pleased God, who, although existing in the flesh, were yet walking after the Spirit.
Openly let us vindicate our disciplines. Sure we are that "they who are in the flesh cannot please God; " not, of course, those who are in the substance of the flesh, but in the care, the affection, the work, the will, of it.
The wise of this world are in the flesh because they cling to their wisdom, by which they reject God’s law. For whatever goes against the law of God is of the flesh, because it is of the world. For the whole world is flesh and every visible thing is assigned to the flesh.
What then? Are we, it will be said, to cut our bodies in pieces to please God, and to make our escape from the flesh? And would you have us be homicides, and so lead us to virtue? You see what inconsistencies are gendered by taking the words literally. For by "the flesh" in this passage, he does not mean the body, or the essence of the body, but that life which is fleshly and worldly, and uses self-indulgence and extravagance to the full, so making the entire man flesh. For as they that have the wings of the Spirit, make the body also spiritual, so do they who bound off from this, and are the slaves of the belly, and of pleasure, make the soul also flesh, not that they change the essence of it, but that they mar its noble birth. And this mode of speaking is to be met with in many parts of the Old Testament also, to signify by flesh the gross and earthly life, which is entangled in pleasures that are not convenient. For to Noah He says, "My Spirit shall not always make its abode in these men, because they are flesh." [Genesis 6:3 as the Septuagint gives it] And yet Noah was himself also compassed about with flesh. But this is not the complaint, the being compassed about with the flesh, for this is so by nature, but the having chosen a carnal life. Wherefore also Paul says, "But they that are in the flesh cannot please God." Then he proceeds:
Are we to cut our bodies to pieces in order to please God? Should we become murderers in order to practice virtue? You see what inconsistencies result if we take these words literally! What Paul means by the flesh in this passage is not the essence of the body but a life which is carnal and worldly, serving self-indulgence and extravagance to the full.
Why is this? Is not the speaker himself clad in flesh? Paul does not mean that those clad in flesh are incapable of pleasing God but rather those who put no store by virtue, whose thoughts are totally carnal and who are caught up in pleasures of that kind, paying no attention to their soul, which is incorporeal and intellectual.
This proves that Paul did not find fault with the flesh itself but with the works of the flesh, because those to whom he was writing were undoubtedly living in the flesh in the physical sense. Once one has given himself over to the flesh (in the spiritual sense) it is impossible to avoid sin.
If all who are carnal cannot please God, how does Paul himself, the speaker, please God? How do Peter and the other apostles and saints, whom we cannot deny were carnal, please him?… It is because they—and we—do not live according to the flesh. We … walk about on the earth, it is true, but we are hastening on our way to heaven, for here we do not have a lasting place, but we are wayfarers and pilgrims, like all our fathers.
[AD 202] Irenaeus on Romans 8:8