[W]hy do we end up suffering while pursuing happiness? That is a fundamental question. The answer is that ordinary people think of happiness as the satisfaction of worldly desires, seeing their lives only from a biological viewpoint. If perfection of our biological lives is our only desire and goal, this world quickly becomes a battlefield of clashing egos, all struggling for survival. Each person pursues his own interests at the expense of the others. In order to achieve true happiness, we must break out of our selfish limitations somehow and find a path which transcends biological existence.
We must first realize that true happiness cannot be the satisfaction of our desires by winning the battle for survival (which is impossible), but rather the establishment of a world without conflicts, where each individual considers the happiness and interests of others to be the same as his own. This is the Buddha’s “Pure World.” (In it, the Buddha is at the center, not I or anyone else.) Its realization is the only path for overcoming sufferings.
Introduction to the Lotus Sutra