Romans 2:15-16

It demonstrates that the requirements of the law are woven into their hearts. They know what is right and wrong, for their conscience validates this “law” in their heart. Their thoughts correct them in one instance and commend them in another. So this judgment will be revealed on the day when God, through Jesus the Messiah, judges the hidden secrets of people’s hearts. And their response to my gospel will be the standard of judgment used in that day.