To be kind, honest and have positive thoughts; to forgive those who harm us and treat everyone as a friend; to help those who are suffering and never to consider ourselves superior to anyone else: even if this advice seems rather simplistic, make the effort of seeing whether by following it you can find greater happiness.
The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents... some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new Dark Age.
Since we desire the true happiness that is brought about by a calm mind, and such peace of mind arises only from having a compassionate attitude, we need to make a concerted effort to develop compassion.