Romans 2:14-16

14(Indeed, when Gentiles, who do not have the law, do by nature things required by the law, they are a law for themselves, even though they do not have the law.

15They show that the requirements of the law are written on their hearts, their consciences also bearing witness, and their thoughts sometimes accusing them and at other times even defending them.)

16This will take place on the day when God judges people’s secrets through Jesus Christ, as my gospel declares.