What “Flesh” Means in This Passage

So in this passage we ought to take “flesh” to mean not man, that is, his material substance, but the will of the flesh and evil desires, just as “spirit” does not mean anything material, but the good and spiritual desires of the soul. The blessed apostle has made this meaning plain just before, where he begins: “But I say, walk in the spirit, and you will not fulfill the desires of the flesh. For the flesh desires against the spirit, and the spirit against the flesh; these are contrary to one another, so that you may not do what you would.” And since these two, the desires of the flesh and of the spirit, exist together in one and the same man, an inner war arises, carried on within us every day. The desire of the flesh, which rushes blindly toward sin, revels in the delights that go with present ease. On the other hand, the desire of the spirit opposes these and wants to be wholly absorbed in spiritual efforts, so much so that it wants to be rid even of the necessary uses of the flesh, longing to be so constantly taken up with these things that it would have no share of concern for the weakness of the flesh. [a]

The flesh delights in self-indulgence and lust; the spirit will not even put up with natural desires. The one wants plenty of sleep and to be filled with food; the other is fed by vigils and fasting, so that it is unwilling to allow even the sleep and food needed for life. The one longs to be rich in plenty of everything; the other is content even without a daily supply of scanty food. The one wants to look sleek from the baths and to be surrounded every day by crowds of flatterers; the other delights in dirt and filth and the solitude of the trackless desert, and shrinks from the approach of any human being. The one lives on the esteem and applause of men; the other glories in the wrongs and persecutions done to it.