He no longer speaks of works, but he rouses them to greater things. For when he was speaking of vice, he mentioned the works of it: but when of virtue, he speaks not of works, but of arms, to show that virtue puts him that is possessed of it into complete safety, and complete brightness. And even here he does not pause, but leading his discourse on to what was greater, a thing far more awestriking; he gives us the Lord Himself for a garment, the King Himself: for he that is clad with Him, has absolutely all virtue. But in saying, “Put on,” he bids us be girt about with Him upon every side. As in another place he says, “But if Christ be in you.” And again, “That Christ may dwell in the inner man.” For He would have our soul to be a dwelling for Himself, and Himself to be laid round about us as a garment, that He may be unto us all things both from within and from without. For He is our fullness; for He is “the fullness of Him that fills all in all”: and the Way, and the Husband, and the Bridegroom;— for “I have espoused you as a chaste virgin to one husband,”: and a root, and drink, and meat, and life—for he says, “I live, yet not I, but Christ lives in me;” and Apostle, and High-Priest, and Teacher, and Father, and Brother, and Joint-heir, and sharer of the tomb and Cross;— for it says, “We were buried together with Him,” and “planted together in the likeness of His Death”: and a Suppliant;— “For we are ambassadors in Christ's stead”: and an “Advocate to the Father;”— for “He also makes,” it says, “intercession for us:” and house and inhabitant—for He says, “He that abides in Me and I in Him”: and a Friend; for, “You are My friends”: and a Foundation, and Cornerstone. And we are His members and His heritage, and building, and branches, and fellow-workers. For what is there that He is not minded to be to us, when He makes us cleave and fit on to Him in every way? And this is a sign of one loving exceedingly. Be persuaded then, and rousing you from sleep, put Him on, and when you have done so, give your flesh up to His bridle. For this is what he intimates in saying,
“And make not provision for the flesh, to fulfil the lusts thereof.” For as he does not forbid drinking, but drinking to excess, not marrying, but doing wantonness; so too he does not forbid making provision for the flesh either, but doing so with a view “to fulfil the lusts thereof,” as, for instance, by going beyond necessaries. For that he does bid make provision for it, hear from what he says to Timothy, “Use a little wine for your stom- ach's sake, and your frequent infirmities.” So here too he is for taking care of it, but for health, and not wantonness. For this would cease to be making provision for it, when you were lighting up the flame, when you were making the furnace powerful. But that you may form a clearer notion what “making provision” for it “to fulfil the lusts thereof” is, and may shun such a provision, just call to mind the drunken, the gluttonous, those that pride themselves in dress, those that are effeminate, them that live a soft and relaxed life, and you will see what is meant. For they do everything not that they may be healthy, but that they may be wanton and kindle desire. But do thou, who hast put on Christ, prune away all those things, and seek for one thing only, to have your flesh in health. And to this degree do make provision for it, and not any further, but spend all your industry on the care of spiritual things. For then you will be able to rouse yourself out of this sleep, without being weighed down with these manifold desires. For the present life is a sleep, and the things in it are no way different from dreams. And as they that are asleep often speak and see things other than healthful, so do we also, or rather we see much worse even. For he that does anything disgraceful or says the like in a dream, when he is rid of his sleep, is rid of his disgrace, also, and is not to be punished. But in this case it is not so, but the shame, and also the punishment, are immortal. Again, they that grow rich in a dream, when it is day are convicted of having been rich to no purpose. But in this case even before the day the conviction often comes upon them, and before they depart to the other life, those dreams have flown away.
Source: Homilies on Romans (New Advent)