From Karma Yoga by Swami Vivekananda
First, we have to bear in mind that we are all debtors to the world and the world does not owe us anything. It is a great privilege for all of us to be allowed to do anything for the world. In helping the world we really help ourselves.
The second point is that there is a God in this universe. It is not true that this universe is drifting and stands in need of help from you and me. God is ever present therein. He is undying and eternally active and infinitely watchful. When the whole universe sleeps, He sleeps not. He is working incessantly; all the changes and manifestations of the world are His.
Thirdly, we ought not to hate anyone. This world will always continue to be a mixture of good and evil. Our duty is to sympathize with the weak and to love even the wrongdoer. The world is a grand moral gymnasium wherein we have all to take exercise so as to become stronger and stronger spiritually.
Fourthly, we ought not to be fanatics of any kind, because fanaticism is opposed to love. You hear fanatics glibly saying, “I do not hate the sinner. I hate the sin,” but I am prepared to go any distance to see the face of that man who can really make a distinction between the sin and the sinner. It is easy to say so. If we can distinguish well between quality and substance, we may become perfect men. It is not easy to do this. And further, the calmer we are and the less disturbed our nerves, the more we shall love and the better will our work be.