Anne Frank said this quote

People who have a religion should be glad, for not everyone has the gift of believing in heavenly things. You don't necessarily even have to be afraid of punishment after death; purgatory, hell, and heaven are things that a lot of people can't accept, but still a religion, it doesn't matter which, keeps a person on the right path. It isn't the fear of God but the upholding of one's own honor and conscience. How noble and good everyone could be if, every evening before falling asleep, they were to recall to their minds the events of the while day and consider exactly what has been good and bad. Then, without realizing it you try to improve yourself at the start of each new day; of course, you achieve quite a lot in the course of time. Anyone can do this, it costs nothing and is certainly very helpful. Whoever doesn't know it must learn and find by experience that: A quiet conscience mades one strong!