Atheism
a - without
theism - belief in the existence of god(s)
An atheist is one who has no belief in any type of deity. No more, no less than that (note that the definition "one who denies the existence of god" is inaccurate as one would have to believe in a god in the first place to be able to deny the existence of that god).
Atheists are not devil worshippers (I would have thought it obvious that not believing in gods also rather strongly implies that one also does not believe in devils).
Atheism has nothing to do with communism - atheists can be from any political background, and their political views are rarely anything to do with their lack of belief in a deity.
Atheism has nothing to do with morals. Atheists can be "good" or "bad" people (although an atheist who does good things does so because he wants to, not because he fears punishment from a god).
The bible is a collection of about sixty books, written by different, mostly anonymous authors, over hundreds of years, hundreds of years ago. It is a book of ancient legends, not history. Anyone who believes that is it the "infallible word of God" cannot have read it properly - it is full of contradictions and absurdities (I would recommend to such people the Skeptics Annotated Bible, which contains the complete King James version and points out the problems as they occur).
God - according to most descriptions - cannot exist. The gods of specific religions are based on ancient texts that have no basis in fact; a universal creator is a logical impossibility (see my post on intelligent design for more on this) and even vague descriptions about an "omniscient, omnipotent and omnibenevolent being" are self contradictory (see this post from the Raving Atheist).
Many people who send comments try to use a simplified version of Pascal's Wager to convert me to Christianity: "it is better to believe than to not believe - if you believe then when you die you gain everything, if you don't believe then when you die you loose everything." There are two problems with this:
1. I cannot make myself believe - I would merely be "going through the motions", which a god would surely be aware of, and
2. The argument can be applied to anything - another god for example. Do Christians also worship Allah "just in case"?
I accept what I know about evolution as being likely, although I am no expert on the subject. However, in the unlikely event of evolution being proved false, it would not make creationism true! It is absurd to believe that the entire universe was created by a god in six days - particularly as the creation story, if taken literally, gives a universe as such:
Click for a larger image
As for justifying this site, Mr_y has done this nicely in his comments to a previous post here. I would like to add the following though:
If Christians were simply an eccentric group of people who went about practicing their strange beliefs in private there would be no problem. However, this is not the case.
At best, Christians preach - which often involves "spreading the word" to vulnerable groups of people and innocent, susceptible children. At worse, Christians attempt to force their views on others by trying to ban things that they don't like and implement their beliefs into law.
These people must be opposed, and the more people who do so the better.