Samsara: the World We Live In
The cycle of life and death
One of the few certainties in life is that we will die, but that doesn't necessarily mean that our minds will cease to exist. In most religions there is some kind of existence after death.
According to Buddhism, during death, in all sentient beings (beings with consciousness), the grossest aspects of the body and mind stop functioning, but not the most subtle aspects of body and mind. This is a form of subtle energy and a very subtle aspect of consciousness that we are not normally aware of, also known as the "spirit flow". It is somewhat similar to what is called the soul in other religions, but the flow of the mind changes continuously, just like a river.
After the dying process we are first of all 'reborn' in an intermediate state (Tibetan: bardo). The mindstream in this state develops grosser aspects of body and consciousness, and it is sometimes compared to the state we are in when we dream. After a maximum of 49 days we 'die' again, and we leave this intermediate state when our karma makes a connection with a new body.
When starting a new life, the reverse of the dying process happens: our mindstream develops gross physical and mental aspects and we start experiencing a physical world again.
Worlds of existence
Not only humans are sentient beings, but all living beings with a mind. When you observe animals closely, you see that they perceive the environment and react to it. They try to avoid poisonous food and pain, just like humans. In general, however, their mental capacities appear to be more limited than humans. For example, animals don't build advanced societies complete with philosophical ideas and complex scientific knowledge.
In addition to animals, however, there are other worlds that we normally cannot perceive. These other realms are actually the result of the karma of the beings who live in them. Simply said; if you have accumulated a lot of positive karma by helping others instead of harming them, you will experience happiness above all else. If the reverse is the case, you will experience an existence with a lot of pain and misery. In all these worlds life is not eternal, and after death your karma will ultimately determine which world of existence you will experience next.
Beings with a lot of positive karma can experience a paradisiacal world after they die, which is called heaven. For lack of a better word, these beings are also called gods. Gods are not perfect, not omnipotent and only have a limited lifespan in spite of their positive karma. Although their lives consist mainly of pleasure and happiness, when they die they realize that they've created no new positive karma and that their next existence will be far less fortunate. Due to this realization about their future rebirth they experience a tremendous amount of fear and stress.
Demigods do lead a comfortable life, but they are plagued with jealousy for the gods who have it even better. This makes it virtually impossible to be content and peaceful.
People generally experience a life which is a mix of both happiness and suffering. And because everyone has a different mix of karmas, we all experience the different, individual results of our specific karma.
The life of animals is primarily dominated by ignorance. Animals mostly react instinctively to their environment to survive, and life is a mix of happiness and suffering. Further, because many animals kill to survive, they are creating the causes for future bad rebirths.
The life of hungry ghosts (pretas in Tibetan) revolves around strong attachments and insatiable desires. It is said that hungry ghosts are constantly hungry and thirsty, but there is no food or drink to be found, and thus they remain in a state of constant suffering.
The life of these beings consists almost exclusively of pain, misery and torment. The only positive thing you can say about life in hell is that it doesn't last forever. Sooner or later, most of the negative karma has matured, and you are reborn in one of the other realms of existence.
The Valuable Human Life
Gods and demigods are very intelligent, but their life is so pleasurable that they have no interest in spiritual development whatsoever.
Animals lack basic intelligence, and pretas and hell-beings are so preoccupied with their suffering that they do not have space or time for spiritual development.
People, on the other hand, have the advantage that by experiencing both pleasure and pain, that they have enough balance in their lives, and intelligence, to have the motivation to want to develop spiritually/religiously to overcome their problems. At the same time (with a bit of luck) they can also find the peace and comfort to devote themselves to these spiritual interests. This is why Buddhism often speaks of 'the precious human life'.
When you look at the world there is a lot of doom and gloom, but fortunately, as humans, we have the opportunity to do something about it.
See the following page: Rebirth