John Calvin Commentary Romans 6:19

"I speak after the manner of men because of the infirmity of your flesh: for as ye presented your members [as] servants to uncleanness and to iniquity unto iniquity, even so now present your members [as] servants to righteousness unto sanctification." — Romans 6:19 (ASV)

I speak what is human, etc. He says that he speaks in 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, even though He spoke of heavenly mysteries, though not as magnificently as the dignity of the things required, because He accommodated Himself to the capacities of a people ignorant and simple.

In this way, the Apostle says, by way of preface, so 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, indeed, base and disgraceful, than for the spiritual grace of Christ to have less influence over them than earthly freedom.

It is as though he had said, “I might, by comparing sin and righteousness, show how much more ardently you ought to be led to render obedience to the latter than to serve the former; but out of regard for your weakness I omit this comparison. Nevertheless, though I treat you with great indulgence, I may still surely make this just demand — that you should not at least obey righteousness more coldly or negligently than you served sin.”

This is a sort of reticence or silence, a withholding of something when we wish more to be understood than what we express. He still exhorts them to render obedience to righteousness with much greater diligence, seeing that righteousness is more worthy than sin, even though he seems not to require this in so many words.

As ye have presented, etc.; that is, “As you were formerly ready with all your faculties to serve sin, it is therefore sufficiently evident how wretchedly enslaved and bound did your depravity hold you to itself. Now then, you 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 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, “You 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 is the case when the faithful devote themselves to serve God in purity.