Sin, also for those who don't have faith, exists when one goes against one's conscience. To listen to and obey it means, in fact, to decide in face of what is perceived as good or evil. And on this decision pivots the goodness or malice of our action.

One must repay good and ill; but why just to the person who did us good or ill?

Some cultures believe a long life brings wisdom. I'd like to think so. Perhaps, part of that wisdom is to recognize some of life's baffling paradoxes such as the way human beings have a huge propensity for good, and yet a capacity for evil.

For our self respect depends upon our ability to make requital, for good or for evil.

And if your friend does evil to you, say to him, ''I forgive you for what you did to me, but how can I forgive you for what you did to yourself?"

For all things are baptized at the font of eternity, and beyond good and evil; good and evil themselves, however, are but intervening shadows and damp afflictions and passing clouds.