When a person believe that God exists, they are a "theist," that is to say, they believe that there is a higher power who either created us or has the ability to greatly affect our lives. Atheists believe that there is no higher being.
What do atheists believe? It is a difficult question to answer, because, unlike most religions, atheists are bound by their disinclination or disbelief in ideology, whereas most people who subscribe to a set of religious beliefs have a text, traditions, or other form of ideology to adhere to. Atheism cannot be classified in the same way that religion can, because it is essentially the exact opposite. Where we classify a person's religion based on their belief in something, we attempt to classify atheists the same way based on their disbelief in a doctrine.
That being said, atheists hold a wide range of beliefs and come to their own moral standards, independently of God and of the church.
The following are all generalizations about atheists, and it is worth noting again that because atheists do not have a standard to adhere to, there is very little to limit their theories and moral reasoning.
What do atheists believe about how the world was created? Atheists tend to believe that the Earth was created during the Big Bang, a scientific event millions of years ago that caused the particles in the universe to become ordered. Through evolution, or the ability of creatures to gradually adapt to their surroundings biologically, we have seen the rise of a many different species of animal and plant life.
What do atheists believe about morality? Atheists have many different influences from which they can derive their moral beliefs. Atheists draw moral theories from philosophers, political leaders, literature, and even religious figures, to name a few. It is a common myth that atheists reject the bible as a whole, and this is generally untrue. Many atheists view the moral advice written in the bible as good advice, much as they may belief that there is good moral advice in any religious tract or text.
What do atheists believe about politics? Again, atheists are as varied on their political views as religious people are. In the United States, religious people are seen as more right-wing, while atheists are seen as more left-wing. This is, of course, a potentially grievous generalization. It does seem that republican view points tend to favor religious conviction, while democratic viewpoints are favorable to atheist ideas. But there are many atheists on both sides of the political spectrum, just as the religious as so divided.
What do atheists believe about religion? Many atheists believe that religion is a greater hurt to the community that it is a help. While it is a myth that atheists are planning some sort of bloody revolution, it is generally true that atheists believe we would have a better, more educated world if no one was religious.
Atheists tend to believe that logic is more important than conviction, fact more important than belief, and material objects are more important that soul.