How and when life began is a mystery and perhaps will always remain so. The theistic religions - Judaism, Sikhism, Islam, Ba'hai and Christianity - all claim that their respective gods created life. But saying that a god created life does not really answer the question of how life coming from life. The theist still cannot explain how God's life began. Apart from legends, there are two scientific theories that attempt to explain how life began on earth. The first, called the Haldane-Oparin Hypothesis after the two scientists who first presented it, says that organic matter came from inorganic matter. According to this hypothesis, a mixture of simple inorganic gases dissolved in the ocean and, energised by ultraviolet light from the sun, resulted in the first prehistoric molecules, such as might be required for the start of life. This is the most widely accepted hypothesis on the origin of life. Recently, Sir Fred Hoyle and Professor Chandra Wickramasinghe have presented an entirely different hypothesis. They suggest that simple life forms evolved in space and were transmitted to earth on meteorites and in the tails of passing comets. But however it began, the earliest evidence of life on earth consists of fossils of rod-shaped structures resembling modern forms of primitive algae and bacteria thought to be about 2.7 billion years old. Almost all scientists believe that these first life forms developed while floating on the surface of the ocean.

Buddhism says that, as in the case of the universe, the ultimate origin of life cannot be known. But the Buddha does explain how life on earth began. At the time when the universe was expanding, beings existed only in a heaven realm.

               And there they dwell, made of mind, feeding on joy, self-luminous, moving through the air and glorious, and there they abide for a long, long time. During that period the world was one mass of water and all was utter darkness. No moon or sun, no constellations or stars could be seen, there were no months or fornights, no years or seasons, nor was there male or female - beings were just beings. And after a long, long time, a savory scum formed over the surface of the waters where those beings were. It looked like the skin that forms on hot milk as it cools. It had the colour of quality ghee or butter, and it was sweet like the taste of pure wild honey. Then some being of a greedy nature said: "I say, what can this be?" And tasted the scum with its finger. When it did this, it liked the taste, and a craving arose. Then other beings did the same thing, and craving arose in them too. So they began to break off pieces and eat them. And as a result of this, their self-luminosity disappeared, and as a result of that, the moon and the sun, night and day, months and fortnights, years and seasons all came into being.

The Buddha then goes on to explain how the bodies of these beings became grosser as they ate, and how sexual characteristics eventually arose. And all of these changes, he says, took place "over a long, long time". Anyone familiar with scientific speculation about the early evolution of life on the planet cannot fail to see how similar it is to what the Buddha says. Both scientific speculation and Buddhist thought agree that the surface of the earth was originally covered with water. Both agree that the first life floated on the surface of the water where it absorbed nutrients. Both agree that early life forms were asexual, and both agree that the evolution from simple organisms into complex ones took place over an immense period of time.

Science categorises life into types according to the structure of the body, while the Buddha categorised life into types according to the quality of experince. The Buddha says that there are six realms of existence, differentiated from each other by the types of experience that the beings in those realms have. There is the deva realm, the human realm, the realm of animals, the realm of hungry spirits, the realm of jealous spirits, and the hell realm. Let us have a look at each of these realms.

Devas are sometimes called gods and their realm is sometimes called heaven, but both these terms are somewhat misleading. The word 'God' suggests the theistic idea of an all-loving, all powerful deity who creates and controls everything and who is utterly different from man. The word 'heaven' suggests the naive theistic concept of an eternal afterlife not unlike life on earth where nothing ever goes wrong, where people in white robes sing songs, and where angels play trumpets. Devas are not perfect or eternal, and, when their lifespan is over, they can be reborn in the human realm just as a human can be reborn as a deva. The main characteristic of the devas is that they experience a great deal of happiness.

Likewise, heaven is not a place completely separate from the other realms of existence; heaven is not 'up there' any more than hell is 'down there'. A deva might dwell right next to a human being or a hungry spirit. What separates them is their different experiences, not their position in space. Because devas might well have been humans before being reborn in the deva realm, they often retain an interest in what humans do. They might answer prayers, protect particular people from danger, or even create problems.

While discussing the differences between devas and gods, it will be useful to see what Buddhism says about the idea of a single perfect creator God. The existence of such a God was denied by the Buddha because he believed the idea to be illogical, lacking in evidence to support it, and unnecessary. There are several arguments used to try to prove the existence of a God, and Buddhism successfully shows that none of these arguments are satisfactory. The first argument for the existence of God goes like this: everything has a cause, so there must be a first cause, and that first cause is God. There are severals objections to this argument. Firstly, this argument contradicts itself. If everything must have a cause, then the first cause must have a cause also. Secondly, there is no logical reason why everything must have a single first cause. Most things we see are produced by multiple causes, so it is just as logical to say that everything has ten, twenty, a hundred or even a thousand first causes. Thirdly, even if there was a single first cause, there is no evidence that that first cause was God. It could just as possibly have been a dinosaur, a flash of lightning or an old boot. And fourthly, it is logically impossible to have a first cause or a beginning of the universe. A beginning is an event which, like every other event, must take place in time. Time consists of past, present and future. For any event to take place, there must be a time before it occured(past), a time in which it occurred (present) and a time after its occurrence (future). Before the supposed creation of everything by God, there could have been no time because nothing existed. And it is clearly impossible for timelessness to give rise to time more than darkness can give rise to light.

Another argument for the existence of God goes like this: everything in nature seems to have an order and a purpose. This could not have happened accidentally, it must have been designed. If nature exhibits design, there must be a designer, and that designer is God. There are several objections to this argument. Firstly, even if it is admitted that nature displays design, there is no evidence that the designer is God or even that there is a single designer. In fact , as nature is so intricate and complex, we would expect it to require many designers. Thus, if anything, nature's apparent design indicates that there are many creator gods. Secondly, although nature does exhibit design, there seems to be many aspects of cruelty in that design. For example, tuberculosis germs have been designed to rot human lungs. The mouth of the lamprey has been designed to latch on to the bodies of fish and then slowly and painfully eat them alive. Leprosy germs are designed to kill human flesh so that extremities drop off the body, causing hideous deformities. So although nature does exhibit design, much of it causes extreme suffering, thus indicating that an all-loving God could not have designed it. The third objection is that although nature does exhibit design, it does, at the same time, often go wrong. If God the designer is perfect, his creation must also be perfect. But nature is far from perfect. Rain waters the crops but the rain often fails to come and millions die of starvation, or sometimes it rains too much and thousands lose their homes and their lives in floods. Every year millions of babies are born with terrible deformities or mental retardation. The production of cells in the body is sometimes faulty, causing tumours and cancers. The fact that nature's design is imperfect indicates that a perfect  creator God could not have designed it.

Buddhism can also offer several well-reasoned arguments as to why there cannot be an all-knowing, all-powerful, all-loving creator God. The first argument goes thus: if God is all-knowing, he must know all the past, all the present and all the future. God must know every choice a person will make, every thought a person will have, and every act he will do long before it happens. Thus a person can only act in the way God has already foreseen; his whole life must be fixed and predetermined. So the idea of an all-knowing God makes free-will impossible, and if man has no free-will, he cannot be held responsible for any of his acts and the idea of trying to do good or avoid evil becomes meaningless.

Related to this, another argument runs thus: if God really created and controlled everything, there would be no point in man doing anything because he would be only a puppet of God's desire and God, not man, would be responsible for any evil that man did. The Buddha states the argument like this:

         There are some ascetics and Brahmins who teach and believe that whatever a person experiences, be it pleasant, painful or neutral, all that is caused by God's will. I went to them and I asked if they did teach such an idea, and they said they did, and I said: "if that is so, venerable sirs, then people must commit murder, theft and adultery because of God's will. They must lie, slander and use harsh and idle speech because of God's will. They must be greedy, hating and full of false views because of God's will." Those who fall back on God's will as the decisive factor will lack the desire and effort to do this or not do that.

        The Buddhist poet, Santideva, puts the idea simply when he says: "If God really is the cause of all that happens, then what is the use of man's striving?"

Another argument against the idea of God runs thus : the existence of a great deal of evil and suffering in the world is proof that an all-loving, all-powerful God does not exist, for if such a God did exist, surely he would act to stop evil and suffering. Even most ordinary, imperfect people would relieve sickness, famine and distress if they had the power. So why doesn't God? Theists will say that suffering is God's punishment for evil-doers. But this cannot be so, because good people are sometimes seen to suffer accidents, sickness and premature death, while evil people are sometimes successful, healthy and happy. The theist will then say that suffering is caused by man's sinfulness. But although man must be held responsible for some suffering, he can hardly be blamed for the suffering that is caused by diseases like cancer, disasters like earthquakes, framines and droughts or terrible things like birth defects. Finally, the theist will say that evil and suffering are caused by devils. But even if this is so, it still doesn't explain why an all-loving God does not save innocent people from unnecessary suffering. Thus the theist cannot explain why an all-loving God allows suffering to happen. In fact, the terrible and apparently meaningless suffering that does exist is convincing proof that all-loving God does not exist. As the Buddha says:

       One with eyes can see the sickening sight; Why does not God set his creatures right? If his wide powers no limit can restrain, Why is his hand so rarely spread to bless? Why does he not to all give happiness? Why do fraud, lies and ignorance prevail? Why triumphs falsehood, while truth and justice fail? I count you, God, one of the unjust among, Who made a world in which to shelter wrong.

Another argument Buddhism puts against the God idea is that the belief in God does not seem to be necessary. Theists are often heard to say that a happy, meaningful life can only be had by believing in God, or that only the belief in God can give strength enough to overcome personal problems. But this is not true. There are millions of people who lead happy, productive and virtuous lives without such a belief. There are just as many who have overcome great handicaps, disabilities and hardships through their own strength and resolution and without belief in God. If a person can be moral, happy and compassionate to his fellows, and have a purpose in life without belief in God, then belief in God is simply not needed. However, it is important to remember that some people do find belief in some form of God meaningful and necessary in their lives. Therefore, while not subscribing to it themselves, Buddhists should respect theism and those who adhere to it.

The human realm(manussa loka) is the best of all realms of existence because it offers the best opportunities to develop spiritually and to attain Enlightenment. The devas experience so much happiness that they have no motivation to develop their minds, while the beings in the lower realms experience so much suffering that they are unable to.  Humans experience about equal proportions of happiness and suffering. The size and structure of the human brain gives consciousness a very wide expression, allowing humans to think, reason and remember. In fact, the ancient Buddhists used to think that the word 'man'(manussa) was derived from the term 'prominence of mind'(mana ussannata). Humans also have highly-developed language, making the clear communication of the Dhamma possible. But although the human realm is the best of all realms, to be born human is a rare privilege indeed, and we should make full use of the opportunities it offers us.

Not only does the human state offer the best opportunities for Enlightenment, but all human beings can attain Enlightenment. The reason for this is that mankind is one. It is important to mention this because some religions and political ideologies claim that different races, castes or classes have different intellectual capacities, and that they should be treated differently and given different opportunties. Hinduism in ancient India taught such an idea, dividing humans into four castes and excluding the lowest, the Sudras, from all social and religious life, claiming that they had no intellectual abilities. The Buddha opposed such ideas most strongly. In dozens of his discourses he used reason and common sense to attack the caste system and to uphold human equality and dignity.

The animal realm(tiracchana yoni) includes all non-human animals - mammals,birds,fish,reptiles and insects. In animals, qualities like loyalty, compassion, self-sacrifice and the like are only very rudimentary, the main motivating factors in their lives being the lower instincts of hunger, sex and survival. Because of this, animals prey on each other without mercy or compassion, and they can expect little help or sympathy from their fellows.

Hungry spirits(peta) are beings whose minds are constantly tormented by longing, wanting and the frustration of not getting what they want, and they wander about trying to relieve their hunger.

Jealous spirits(asura) are given that name because they are tormented by jealousy and covetousness. The happiness of others, especially of the devas, makes them rage with envy.

Beings who experience a lot of pain are said to be in Hell (niraya). The pain they feel is not physical, but rather the pain of anxiety, fear, remorse and depression.

Although the realms of existence are places, they are more than that; they are primarily states of mind. A human who has beauty, power and happiness can be said to be in a deva realm just as much as a deva is. Likewise, a human who experiences great emotional suffering can be said to be in hell just as much as a hell being is. The Buddha makes it clear when he says:

        When the average ignorant person says that hell is under the sea, he is saying something that is false and without basis. The word 'hell' is a name for painful feelings.