Romans 2:14-16

2:14 For whenever the Gentiles, who do not have the law, do by nature the things required by the law, these who do not have the law are a law to themselves. 2:15 They show that the work of the law is written in their hearts, as their conscience bears witness and their conflicting thoughts accuse or else defend them, 2:16 on the day when God will judge the secrets of human hearts, according to my gospel through Christ Jesus.