Saint Augustine, The City of God, Vol. II

This he explains more openly a little later: In the law, no one is justified, and to the Galatians: Knowing that a man is not justified by the works of the law. According to this, it is understood: And the Word was made flesh, that is, man; those who do not correctly accept this have thought that a human soul was missing in Christ. For just as the part is taken for the whole, where the words of Mary Magdalene are read in the Gospel, saying: They have taken my Lord, and I do not know where they have laid him, when she was speaking only of the flesh of Christ, which she thought had been taken away from the tomb: so too is man understood when "flesh" is named as a part of the whole, just as in those instances we mentioned above.

Since, therefore, divine scripture names "flesh" in many ways, which would be long to search through and collect, in order to be able to investigate what it is to live according to the flesh (which is certainly an evil, although the nature of the flesh itself is not an evil), let us carefully inspect that place in the epistle of Paul the Apostle which he wrote to the Galatians, where he says: Now the works of the flesh are manifest, which are fornication, uncleanness, luxury, the serving of idols, sorcery, enmities, contentions, emulations, animosities, dissensions, heresies, envies, drunkenness, revellings, and such like; which I tell you, as I have foretold, that they who do such things shall not possess the kingdom of God. This entire passage of the apostolic epistle, as much as will suffice for the present matter, will be able to resolve this question for one considering it: what it is to live according to the flesh. For in the works of the flesh, which he said are manifest and which he enumerated...