Hypothesis, thesis, antithesis, synthesis. The proper methodology. Atheism is based on scientific thinking, not on any kind of belief.

I think the question is set up incorrectly. I don't "believe" there are no gods. I simply lack belief and any gods. My atheism isn't an assertion but rather a rejection of the claim that others make. No belief required.

The complete lack of any compelling evidence that a deity exists.

I am happy to be agnostic thanks to reason, and atheist by belief, and I do not find the two at odds. But it all depends how you define the words, and I am not interested if anyone else wants to redefine my words for me.

An Atheist does not believe that no deities exist, instead they do not believe that deities exist. By one is a positive claim of belief and the other a lack of belief, with which the lack of belief being the actual definition of an Atheist. As an Atheist, I am unconvinced that a god exists and can exist but I am not unwilling to consider the possibility that one does or can, I am simply unconvinced of it. Saying "I don't believe you can do 3 back flips in a row." Is similar but not the same as "I believe you can't do 3 back flips in a row." To put it in non-god terms.

Evolution has no place for a god. What would the purpose be except for the purpose man gives it. The evidence isn't to prove there isn't a god. The evidence is there to prove there is a god for whoever wants to believe in that sort of insanity. I'm not anybody with a label attached to me. I'm sane not insane.

So, agnostic by itself is a bit of a useless term for me. It says nothing of what you actually believe/are convinced of. For example, there are people who do and do not believe in a god or gods, yet understand they don't know for certain. So, under the general agnostic label, all these people with mutually exclusive beliefs would be in the same category... making it utterly useless. This gets especially tricky when you realize it is epistemologically impossible to prove a negative. So if you only use the agnostic label, then people would have to be agnostic on everything that has not yet been proven true. Once again, this does nothing to separate those who believe in said thing vs those who don't.

This is why I prefer the dual system and classify myself as an agnostic atheists. I don't believe there is a god or gods because I have not been convinced of such. Just like I do not believe in pixies, warlocks or fire breathing dragons for the same reason. I understand I don't have all the answers, but withhold belief until the burden of proof is met to my satisfaction

I'm sure there have been plenty that have said the same thing in the preceding 410 comments...but here goes.

Because there is no good evidence of the existence of a god, I am an atheist. I do not believe a god exists.
Because I don't claim to "know" if there is any diety or not, I'm agnostic. Therefore, I'm an agnostic atheist.
I never claimed that "no diety exists" because that would require evidence showing such, which is impossible.
I'm currently convinced that there are no supernatural gods, etc. but I'm certainly not going to claim that I KNOW that there are none.

Personally I feel that the majority of the population is actually agnostic atheist, even though very few will admit to it. I feel that if someone actually believed in whatever god they claim to, there would be NO question about following the rules of that religion.
If I actually was a christian, not an agnostic atheist claiming to be a christian, there is NO WAY I would be doing anything to jeopardize my immortal soul for the blink of an eye that this life on earth would then be.
I would also be scared to death of messing up. I'd go out of my way to make sure to do everything right and by the rules.
But that's not how religious people are for the most part. In fact, I don't know if I've ever met anyone , no matter how religious they claim to be, that hasn't done plenty in their life to warrant eternal hellfire and damnation. So to those people I say that they don't actually believe, but aren't sure, so they're agnostic atheist.

On the other hand, (I'll probably piss some people off here) I think that anyone that claims that they KNOW there are no supernatural entities of any kind, well I think they're idiots. That's just something you can't know. It defies all logic to claim that you KNOW something that by definition can make itself unknowable.

Then there's the gnostic theists, those that claim that they KNOW god exists. They are either 1. liars, or 2. delusional, in my opinion of course. If you claim that you KNOW there is a god, and don't even entertain the possibility that you could be mistaken, well....

So basically, I feel that anyone that is honest and of sound mind is in fact agnostic, although they are surely leaning towards the theistic or atheistic side in varying degrees.

Because nobody has presented any real evidence of a deity.

Simple common sense and lifelong observation of people and their need to belong to something. I think godd and religions are an inevitable result of intellect combined with that need.

Simply, since NO-ONE has ever, can ever show undeniable Proof Positive that ANY Supreme Deity/God has ever existed or exists except in the minds of those who choose to believe/think that it SHOULD ergo, " If it walks like a Duck, Quacks like a Duck then it must be, logically a Duck," so it goes for God/Gods and religion in my opinion.
Plus, after studying Theology and Comparative Modern Religions and gaining my ThD ( Doctorate in the same as an Atheist with an open mind) realising that all religions are merely conjectures and philosophies ( Theosophies is the term I prefer to apply to them) are utterly incapable of withstanding any examination/s using simple reasoning and logic and that they also follow the ages old formula of " When inventing/creating a Deity/Deities one must first remember to create such as being Invisible, Intangible, Unimpeachable, contain all of the traits of human kind, both good and bad, be controlling and demanding, dictatorial and assumedly kind, caring and benevolent as well as being miserly, tight-fisted and completely ambivalent and ambiguous."

To say Atheism is a belief is to tacitly buy into the religious definition of faith. Atheism is not a faith, it is concentrated doubt, that follows the flow of evidence rather than trying to pathetically swim upstream.

I reckon agnostics are just sitting on the fence.
A real atheist doesn't even recognize it as a valid question.
To say that nobody can KNOW that there is no God, falls into the trap of taking the concept seriously. If you can't KNOW that there is no God, then you can't KNOW that you're alive, you can't KNOW that you are not a simulation running on a super-computer, you can't KNOW that your head isn't constructed out of sewing needles. See where it ends up? You can make up any kind of garbage you like, and then say that you can't KNOW that it isn't true,.... but it's all still based on the same logical flaw.
For me,.. ANYTHING which needs to be believed is automatically false. For all intents and purposes, in a real world, things simply are true or not. And belief in a fantasy sky fairy is no different to believing that you are a fish.

It is the same reason I don't believe in big foot, ghosts , fairies or that intelligent aliens have visited the earth. There is simply no evidence. And the existence of complex, intelligent life is not a sufficient arguement because that is just an arguement from incredulity if one thinks it requires a deity to exsist. We have enough evidence from naturalism to hypothesis an explanation for complex life.

The Universe does operate under rules and fundamental laws.  What is their origin?

I'm a newly turned agnostic and triggered by the same thought as yours. I don't believe there is no god, I'll place my bets that there is one.

But since he made us as a creature of free will, think of it from this angle- the moment he chooses to reveal himself, the whole notion of free will becomes invalid. In order to keep the status "free", god must be a silent observer only. No interference, no contacts, no nothing.

This for me solves the dilemma rather peacefully. If God wanted to contact/instruct us, there are literally endless means (rather than the traditional bullshits we currently see in societies). At the same time, this also spares us from the stupid question of disproving God's existence.

Simply put, your question supplies it's own resolution.
As an ex Catholic, I was subject to the concepts of 'Belief' and 'Faith' very early on.
As I got older, I parted company with the church fir many reasons, the most important for me being my development of 'Understanding'.
Nowadays, I spend much less time worrying about filling gaps in my knowledge with self grown belief. What matters is what you as an individual understand and what we as a society are capable of developing in the future. We rest less and less on the ever more complex shoe Horning of the Bible onto gaps in knowledge. The politico social texts of ancient Middle Eastern thinkers is no longer relevant.
It is not belief if it is understanding.

I don't believe no deity exists, as I'm an Atheist. An Atheist simply lacks a belief in things where the evidence is lacking, like Leprechauns, Santa Claus, and god.

Show me the proof

Absence of evidence is evidence of absence.

Atheism means you don't have a belief in God, not that you know one doesn't exist.

Great quesiton. Looking at all the responses there's a lot of common threads here. Where's the proof?

I don't believe he doesnt exist. there is just no evidence for his existence.

I believe that their are more things in heaven and earth, than are dreamed of in religious philosophy. Currently, I have come to the belief that this reality, and everything that I perceive within it, spring from the infinite singularity that is my consciousness.

This is an excellent question. People who are dogmatic about saying there is No God are no different than a dogmatic fundamentalist Christian in my book. A good place to start a scientific search on what is really going on in this area is to take a look at a retired Australian lawyer named Victor Zammit who has written a book entitled "A Lawyer looks at Afterlife Evidence that is Admissable in a Courtroom." He has done a great job regarding this subject and I keep a copy of his book in my home to loan to folks who indicate an interest in looking further. Highly recommended.