John Calvin Commentary Romans 3:5

"But if our righteousness commendeth the righteousness of God, what shall we say? Is God unrighteous who visiteth with wrath? (I speak after the manner of men.)" — Romans 3:5 (ASV)

But if our unrighteousness, etc. Though this is a digression from the main subject, it was still necessary for the Apostle to introduce it, so that he would not seem to give to the ill-disposed an occasion to speak evil, which he knew would be readily seized by them.

For since they were watching for every opportunity to defame the gospel, they had, in the testimony of David, what they might have taken for the purpose of founding a calumny — “If God seeks nothing else but to be glorified by men, why does he punish them when they offend, since by offending they glorify him?

“Without cause then surely is he offended, if he derives the reason of his displeasure from that by which he is glorified.” There is, indeed, no doubt that this was an ordinary, and everywhere a common calumny, as it will soon appear.

Therefore, Paul could not have covertly passed it by. So that no one would think that he expressed the sentiments of his own mind, he states first that he adopts the persona of the ungodly.

At the same time, he sharply touches on human reason with a single expression, whose work, as he intimates, is always to bark against the wisdom of God; for he says not, “according to the ungodly,” but “according to man,” or as man.

And this is indeed the case, for all the mysteries of God are paradoxes to the flesh. And it possesses so much audacity that it does not fear to oppose them and insolently assail what it cannot comprehend.

We are therefore reminded that if we desire to become capable of understanding them, we must especially labor to become freed from our own reasoning (proprio sensu), and to surrender ourselves, and unreservedly submit to his word.

The word wrath, understood here as judgment, refers to punishment, as if he were saying, “Is God unjust, who punishes those sins which set forth his righteousness?”