Romans 3:6 - John Gill's Exposition of the Entire Bible

God forbid, for then how shall God judge the world?] חלילה, "far be it"; such a notion is detestable and abominable, nor can it be fairly deduced from what is asserted; for it is the unrighteousness of his own people, on whom he takes no vengeance personally, and not the unrighteousness of others, on whom he does take vengeance, which commends his righteousness; and supposing it was that of others, God cannot be unrighteous in performing his threatenings, in a way of righteousness: moreover, unrighteousness is sin, and does not of itself but by accident, illustrate the righteousness of God; wherefore God is not unjust in punishing it; for how should God "judge the world?" whereas nothing is more certain than that he will do it, and that this will be done in righteousness; which could not be, was he unrighteous in taking vengeance; which will be one considerable part of that righteous judgment.