It is required in order to reach enlightenment, which is the highest spiritual state. It requires an acknowledgment of self, a knowledge of the four truths of the world—among them that the world is empty and that there is suffering everywhere—but also requires the ability to put the pain out of mind and to focus on the eternal aspects of the world.
Confucius was much more interested in practical life and little time to discuss transcendence and spiritual enlightenment. He was much more considered with ordering lives and polities along ethical lines. Like Buddha however, this ordering requires a balance or moderation that looks very dimly on things like self-indulgence. The middle path is something that hands in hand with the sort of daily etiquette and responsibility that Confucianism describes as intrinsic to moral knowledge.
Both of these Asian philosophies have been enormously philosophically influential. Both took different views on how one achieves the highest levels of knowledge in this world.