19. I speak after the manner of men because of the infirmity of your flesh: for as ye have yielded your members servants to uncleanness and to iniquity unto iniquity; even so now yield your members servants to righteousness unto holiness.
19. Humanum dico propter infirmitatem carnis vestræ, quemadmodum exhibuistis membra vestra serva immunditiæ et iniquitati in iniquitatem, sic et nunc exhibite membra vestra serva justitiæ in sanctificationem.
19. I speak what is human, etc. He says that he speaks after the manner of men, not as to the substance but as to the manner. So Christ says, in John 3:12, that he announced earthly things, while yet he spoke of heavenly mysteries, though not so magnificently as the dignity of the things required, because he accommodated himself to the capacities of a people ignorant and simple. And thus the Apostle says, by way of preface, that he might more fully show how gross and wicked is the calumny, when it is imagined, that the freedom obtained by Christ gives liberty to sin. He reminds the faithful at the same time, that nothing is more unreasonable, nay, base and disgraceful, than that the spiritual grace of Christ should have less influence over them than earthly freedom; as though he had said, |I might, by comparing sin and righteousness, show how much more ardently ye ought to be led to render obedience to the latter, than to serve the former; but from regard to your infirmity I omit this comparison: nevertheless, though I treat you with great indulgence, I may yet surely make this just demand -- that you should not at least obey righteousness more coldly or negligently than you served sin.| It is a sort of reticence or silence, a withholding of something when we wish more to be understood than what we express. He does yet exhort them to render obedience to righteousness with so much more diligence, as that which they served is more worthy than sin, though he seems not to require this in so many words.
As ye have presented, etc.; that is, |As ye were formerly ready with all your faculties to serve sin, it is hence sufficiently evident how wretchedly enslaved and bound did your depravity hold you to itself: now then ye ought to be equally prompt and ready to execute the commands of God; let not your activity in doing good be now less than it was formerly in doing evil.| He does not indeed observe the same order in the antithesis, by adapting different parts to each other, as he does in 1 Thessalonians 4:7, where he sets uncleanness in opposition to holiness; but the meaning is still evident.
He mentions first two kinds -- uncleanness and iniquity; the former of which is opposed to chastity and holiness, the other refers to injuries hurtful to our neighbour. But he repeats iniquity twice, and in a different sense: by the first he means plunders, frauds, perjuries, and every kind of wrong; by the second, the universal corruption of life, as though he had said, |Ye have prostituted your members so as to perpetrate all wicked works, and thus the kingdom of iniquity became strong in you| By righteousness I understand the law or the rule of a holy life, the design of which is sanctification, as the case is when the faithful devote themselves to serve God in purity.