Buddhism traditionally offers two broad ways of understanding a person's lifespan. One is that everything about our lives, from birth to death, is determined by karma, the effects of causes made in past lives and up until this point. A virtuous way of life would have created the causes to be born in pleasant circumstances and enjoy a long life. Destructive and harmful actions, on the other hand, diminish one's vitality, shortening the time one can enjoy life as a human being.
In many Buddhist traditions, because birth into this impure world is itself regarded as a form of suffering, the goal is to purify one's life and karma until one can completely escape the cycle of birth and death.
From another perspective, however, genuine joy lies not in simply being able to avoid or escape from one's own suffering, but in freeing others from their suffering. In other words, the greatest value in life lies in the desire to live and work for the benefit of others. Buddhism terms this desire the "bodhisattva vow," and it is this motivation that determines the nature and course of our lives.
The bodhisattva vow could be described as the original impetus of our lives. Buddhist practice is a way of "remembering" this vow, of engraving it ever deeper in our hearts.
The "Life Span" chapter of the Lotus Sutra, parts of which are recited daily by SGI members around the world, clarifies that the Buddha nature--the universal law, or dharma, to which the Buddha awakened--is inherent in the lives of all people. This Buddha nature is the essence of life, and to awaken to it is to awaken to the eternal aspect of our own lives.
From this perspective, our original essence is pure and undefiled, but we willingly take on negative karma, choosing to be born in difficult circumstances or with various physical or psychological challenges in order to give hope to others by triumphing over these difficulties. By showing proof of the inherent power of our humanity to overcome suffering, we open the way for others to do the same. Likewise, we are able to give real support to people who suffer from similar difficulties. In each new life, we again awaken to our original vow and joyfully embrace whatever challenges it presents us.
Such awakening transforms our experience of life from a cycle of suffering to one of mission.
According to this understanding, even a short life may create lasting value in the lives of those with whom one is connected. A child who dies young, for example, may inspire her parents to think deeply about the nature of life, causing them to live more purposefully.
It is not, then, simply the length of one's lifespan that determines the value of one's life, but the extent to which we are able to create positive value, enhancing our own happiness and that of others.
More than simply an intellectual belief or understanding, an awakening to the eternal nature of our lives is felt as a deep sense of confidence in the face of life's constant and inevitable challenges.
Such awareness does not remove us from the difficult realities of living and dying but it empowers us to confront them with renewed courage and confidence. As Nichiren describes it, we are able to repeat the cycle of birth and death secure upon the "earth" of our intrinsic enlightened nature.
A belief in the eternal nature of our lives does not diminish the significance of our present lives, which Buddhism sees as infinitely precious. Buddhism teaches, rather, that we should strive to live as long as possible, for each day presents new opportunities to pursue a noble and contributive way of life. It is when we live with a dedication to this ideal that we are able to bring forth the luster of our humanity, extend our lifespan and enjoy the most fulfilling and meaningful existence.