Buddha had always reminded his audience that things are impermanent, including life. Everything is forever changing. He insisted that his followers shoud observe and meditate on those in order to recognize them as a first-hand experience.
Let us try some observations. From the human to the material world, there is nothing that does not change. In the human body, cells split, grow and die incessantly. Through the processes, the cells transform an egg and a sperm into a cute baby; a baby into a youthful teenager; a teenager into a loving, beautiful young woman; a young woman into a delicate wife and an adorable mother; and then, all traits of beauty of an energetic life eventually fade away and are replaced by a frail, unpleasant silhouette waiting for disintegration. How pitiful and ephemeral human life is! Even in the United States where the advancement of medicine and technology can prolong life to over a hundred years, people cannot stay strong and free from illness. All elderly people are dying to pass away from their unproductive years. This Law of Impermanence, thus, applies to all beings. No one can escape it. Because it is an eternal truth.
Or take a look at a brand new car. No matter how much care you put into it, after three to five years the car shows signs of wear and tear. Finally, it will be winding into a wreckage.
And look at any relationship. None of them will last forever. As time passes, neighbors move out, friendships disappear, even kinship loosens, not to mention marital loves.
We are suffering because we do not understand the law, nor do we acknowledge it. We wish to stay young forever, avoiding sickness and death. We lament our health when sick, and are terrified when death shows up at our doorstep.
Or we want to be always rich, to experience a comfortable life or satisfaction, to have a wonderful family with a handsome or beautiful spouse and smart children. We are afraid of adversity and of any changes.
Therefore, some of us come to Buddha, unfortunately, not for the truth in his teachings, but because of wrong thoughts that we can pray Buddha for whatever we want. No wonder people become increasingly greedy and miserable, despite the fact that they go to temple very often.
Should we understand and recognize the Law of Impermanence, we could change our perspective toward life. We would admit life as it is, no matter what kind of change or adversity we encounter. That is the teaching of Buddha. We would be brave and wise in any circumstance, and more sympathetic to others. Never again would we cry when facing a mishap, an illness, or even death. And that is the appropriate view, from which Zen Master Van Hanh in the Lý dynasty put into verse, regarding life and human conditions:
The human body, like lightning, appears and departs,
As tree grow in Spring and droop in Fall.
Despite its growth or ruin, we should be not alarmed,
Considered dewdrops on tips of grass as they are all.
However, there are critics who interpret Buddhist viewpoint to be discouraging, or even fatalistic. If things are always changing and human lives are predetermined to suffer and die, why do we bother to maintain a constructive and decent life? Not only does this interpretation misconstrue the Teaching; it represents a shallow thought.
With an earnest observation, it is true that life is forever changing? But facing a truth, one can react either negatively or positively, depending or his or her point of view. The Buddhist teaching, in reality, broadcasts a positive viewpoint. The aforementioned verse has proved it. Life is as short as a lightning, which appears and departs in a blink, or as trees that grow in the Spring and droop in the Fall. Nothing remain unchanged. Despite many changes, an enlightened would recognize them as they are, considering them as dewdrops on tips of grass.
(A dewdrop is so beautiful, especially under the early morning sun. But it won't last long. And certainly nobody is going to cry when a dewdrop liquefies; because that is the way it is).
Moreover, Prince Siddhartha became Buddha only because of his positive outlooks. After witnessing the pain and bitterness of his destitute, sick, and dying people through his rare outing trips, he took a solemn promise to search for a Way capable of erasing all human suffering. In other words, his wished to bring happiness to all human in this painful world.
In order to realize his vows, he bravely renounced his life of luxury and prestige and went into the wilderness for an ascetic life. Later on, after attaining the Way, the Buddha proclaimed that to successfully follow his path, one should arm oneself with some degrees of intelligence, compassion, and courage.