The circle of life is a symbolic representation of birth, survival and death. The idea of life as a circle or a wheel exists across multiple religions and philosophies. Some wheels or circles are considerably more complex than others.
Life is represented as a circle because it is a constant loop. People are constantly born and are constantly dying. There is a spiritual element to the circle, however, in the idea that the end of one existence is not necessarily the end of life altogether. Many religions and philosophies believe that through a certain life path, another life (usually a better one) awaits after humans leave this one. Thus, when humans die, they are not dead but merely reborn to begin another circle of life. In Buddhism, desire, hate and ignorance are at the center of the circle, and humans are forever trying to circumvent them. The Buddhist wheel of life also represents two ascending and descending half circles to represent that not everyone is able to overcome life's challenges. When this happens, one must begin again. This concept is not completely exclusive from the Christian notion of being born again. Christians believe that before anyone can ascend to Heaven, they must be reborn through Christ.