Romans 2:12

For as many as have sinned without law
This is an instance of the strict justice of God, and proves him to be no respecter of persons; for the Gentiles, who were "without law", the written law of Moses, not without the law of nature in their breasts, nor without some civil laws and statutes of their own; inasmuch as they "sinned" against the God of nature, and the law and light of nature, they

shall also perish without law:
not that their condemnation and perdition will be illegal, or not in due course of law; but it will not proceed upon, or according to the law of Moses, they never had; and much less for not believing in Christ, of whom they never heard; but their perdition will be for their sins committed without the law of Moses, against the law of nature: their not having the written law of Moses will be no plea in their favour, or be a reason why they should not be condemned; their persons will not be regarded as with or without the law, but their sins committed by them, to which facts their consciences will bear witness:

and,
so on the other hand,

as many as have sinned in the law;
who have been in and under the law of Moses, and have sinned against it, meaning the Jews:

shall be judged by the law;
and condemned by it, as they were in this world, and will be hereafter: their having this law will be no bar against their condemnation, but rather an aggravation of it; their hearing of it will be no plea in their favour; nor their doing of it neither, unless they could have done it to perfection; for perfect obedience it requires, as a justifying righteousness, otherwise it curses, condemns, and adjudges to death.