Here again, he does not mean flesh absolutely, but such sort of flesh, that which was in a whirl and thraldom of passions. Why then, it may be said, does he not say so, nor state any difference? It is to rouse the hearer, and to show that he that lives aright is not even in the body. For inasmuch as it was in a manner clear to every one that the spiritual man was not in sin, he states the greater truth that it was not in sin alone, that the spiritual man was not, but not even in the flesh was he henceforward, having become from that very moment an Angel, and ascended into heaven, and henceforward barely carrying the body about. Now if this be your reason for disparaging the flesh, because it is by its name that he calls the fleshly life, at this rate you are also for disparaging the world, because wickedness is often called after it, as Christ also said to His disciples, “You are not of this world;” and again to His brethren, He says, “The world cannot hate you, but me it hates.” And the soul too Paul must afterwards be calling estranged from God, since to those that live in error, he gives the name of men of the soul. But this is not so, indeed it is not so. For we are not to look to the bare words, but always to the sentiment of the speaker, and so come to a perfectly distinct knowledge of what is said. For some things are good, some bad, and some indifferent. Thus the soul and the flesh belong to things indifferent, since each may become either the one or the other. But the spirit belongs to things good, and at no time becomes any other thing. Again, the mind of the flesh, that is, ill-doing, belongs to things always bad. “For it is not subject to the law of God.” If then you yield your soul and body to the better, you will have become of its part. If on the other hand thou yield to the worse, then are you made a partaker of the ruin therein, not owing to the nature of the soul and the flesh, but owing to that judgment which has the power of choosing either. And to show that these things are so, and that the words do not disparage the flesh, let us take up the phrase itself again, and sift it more thoroughly. “But you are not in the flesh but in the Spirit,” he says. What then? Were they not in the flesh, and did they go about without any bodies? What sense would this be? You see that it is the carnal life that he intimates. And why did he not say, But you are not in sin? It is that you may come to know that Christ has not extinguished the tyranny of sin only, but has even made the flesh to weigh us down less, and to be more spiritual, not by changing its nature, but rather by giving it wings. For as when fire comes in company with iron, the iron also becomes fire, though abiding in its own nature still; thus with them that believe, and have the Spirit, the flesh henceforth goes over into that manner of working, and becomes wholly spiritual, crucified in all parts, and flying with the same wings as the soul, such as was the body of him who here speaks. Wherefore all self-indulgence and pleasure he made scorn of, and found his self-indulgence in hunger, and stripes, and prisons, and did not even feel pain in undergoing them. And it was to show this that he said, “For our light affliction, which is but for a moment,” etc. So well had he tutored even the flesh to be in harmony with the spirit. “If so be that the Spirit of God dwell in you” (εἴπερ.) He often uses this “if so be,” not to express any doubt, but even when he is quite persuaded of the thing, and instead of “since,” as when he says, “If it is a righteous thing,” for “seeing it is a righteous thing with God to recompense tribulation to them that trouble you.” Again, “Have ye suffered so many things in vain, if it be yet in vain?”
“Now if any man have not the Spirit of Christ.” He does not say, if you have not, but he brings forward the distressing word, as applied to other persons. “He is none of His,” he says.
Ver. 10. “And if Christ be in you.”
Again, what is good he applies to them, and the distressing part was short and parenthetic. And that which is an object of desire, is on either side of it, and put at length too, so as to throw the other into shade. Now this he says, not as affirming that the Spirit is Christ, far from it, but to show that he who has the Spirit not only is called Christ's, but even has Christ Himself. For it cannot but be that where the Spirit is, there Christ is also. For wheresoever one Person of the Trinity is, there the whole Trinity is present. For It is undivided in Itself, and has a most entire Oneness. What then, it may be said, will happen, if Christ be in us? “The body is dead because of sin; but the Spirit is life because of righteousness.” You see the great evils that come of not having the Holy Spirit; death, enmity against God, inability to satisfy His laws, not being Christ's as we should be, the want of His indwelling. Consider now also what great blessings come of having the Spirit. Being Christ's, having Christ himself, vying with the Angels (for this is what mortifying the flesh is), and living an immortal life, holding henceforward the earnests of the Resurrection, running with ease the race of virtue. For he does not say so little as that the body is henceforward inactive for sin, but that it is even dead, so magnifying the ease of the race. For such an one without troubles and labors gains the crown. Then afterward for this reason he adds also, “to sin,” that you may see that it is the viciousness, not the essence of the body, that He has abolished at once. For if the latter had been done, many things even of a kind to be beneficial to the soul would have been abolished also. This however is not what he says, but while it is yet alive and abiding, he contends, it is dead. For this is the sign of our having the Son, of the Spirit being in us, that our bodies should be in no respect different from those that lie on the bier with respect to the working of sin (so the manuscripts Sav. “of the body.” The preceding words are slightly corrupt.) But be not affrighted at hearing of mortifying. For in it you have what is really life, with no death to succeed it: and such is that of the Spirit. It yields not to death any more, but wears out death and consumes it, and that which it receives, it keeps it immortal. And this is why after saying “the body is dead,” he does not say, “but the Spirit 'lives,'” but, “is life,” to point out that He (the Spirit) had the power of giving this to others also. Then again to brace up his hearer, he tells him the cause of the Life, and the proof of it. Now this is righteousness; for where there is no sin, death is not to be seen either; but where death is not to be seen, life is indissoluble.
Ver. 11. “But if the Spirit of Him that raised up Jesus from the dead dwell in you, He that raised up our Lord shall also quicken your mortal bodies by His Spirit that dwells in you.”
Source: Homilies on Romans (New Advent)