Is Our God Who Inflicts Wrath Unjust?

"Though this is a digression from the main subject, it was yet necessary for the Apostle to introduce it, lest he should seem to give to the ill-disposed an occasion to speak evil, which he knew would be readily laid hold on by them. For since they were watching for every opportunity to defame the gospel, they had…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." [This] is…everywhere a common calumny, as it will presently appear. Hence Paul could not have covertly passed it by; but that no one should think that he expressed the sentiments of his own mind, he premises that he assumes the person of the ungodly; and at the same time, he sharply, touches, by a single expression, on human reason; whose work, as he intimates, is ever to bark against the wisdom of God; for he says not, "according to the ungodly," but "according to man," or as man. And thus indeed it is, for all the mysteries of God are paradoxes to the flesh: and at the same time it possesses so much audacity, that it fears not to oppose them and insolently to assail what it cannot comprehend." – J. Calvin