When a person is in a miserable situation, then, yes, it is difficult to develop genuine compassion toward others. That's why I find it difficult to say to poor people, "Please have compassion toward millionaires." That's not easy.
I think there is a complicated side effect to overcoming evil in that we are forever changed by it. I think after we ingest some of the cruelty of the world, it takes years off of our lives, but it also gives us wisdom and a little grace, hopefully a sense of compassion.
True happiness comes from having a sense of inner peace and contentment, which in turn must be achieved by cultivating altruism, love and compassion, and by eliminating anger, selfishness and greed.
We live in a culture that discourages empathy. A culture that too often tells us our principle goal in life is to be rich, thin, young, famous, safe, and entertained.
How can one be compassionate if you belong to any religion, follow any guru, believe in something, believe in your scriptures, and so on, attached to a conclusion? When you accept your guru, you have come to a conclusion, or when you strongly believe in god or in a saviour, this or that, can there be compassion? You may do social work, help the poor out of pity, out of sympathy, out of charity, but is all that love and compassion?
Are you trying to grasp the quality of intelligence, compassion, the immense sense of beauty, the perfume of love and that truth which has no path to it?
What is the relationship between spirituality and ethical practice? Since love and compassion and similar qualities all, by definition, presume some level of concern for others' well-being, they presume ethical restraint. We cannot be loving and compassionate unless at the same time we curb our own harmful impulses and desires.
It is not enough simply to wish that love and compassion should increase in us. We need to make a sustained effort, again and again, to cultivate the positive aspects within us - and the key here is constant familiarity. The nature of human thoughts and emotions is such that the more you engage in them, the more you consciously develop them, the more powerful they become.