Romans 2:12-16

For as many as have sinned without the law shall also perish without the law: and as many as have sinned under the law shall be judged by the law; for not the hearers of the law are just before God, but the doers of the law shall be justified; (for when Gentiles that have not the law do by nature the things of the law, these, not having the law, are the law unto themselves; in that they show the work of the law written in their hearts, their conscience bearing witness therewith, and their thoughts one with another accusing or else excusing them); in the day when God shall judge the secrets of men, according to my gospel, by Jesus Christ.