Hey, I'm known for being bull-headed about some things. I like to qualify my statements, so I'll do so. Using THESE DEFINITIONS, ...
Belief is a mental condition or attitude regarding some specific subject for which the condition or attitude is capable of guiding or directing a being's decisions and actions relevant to that subject. This definition primarily considers human beings but does not rule out other beings capable of making decisions. It specifically rules out any entity that is incapable of choosing alternative behavior in given conditions where/when such alternatives exist.
Faith is a form of Belief that exists without proof of the condition or proof of correctness of the attitude. Believing in God is a form of Faith since proof is not going to happen with God. (I'm not being intransigent on that point, either. The Bible itself tells us we need faith; that the Kingdom is not of this world; and that we must not test God, which is a form of searching for proof.)
Based on those definitions, I have no faith in the existence of God. I believe there is no God. This makes me an atheist because theism is also about belief and faith - but the theist has faith that I do not.
I arrive at this position by rejecting the circular logic based this kind of cycle: "Who inspired the Bible?" Answer: "God" ... followed by "How do we know there IS a God?" Answer: "The Bible tells me so."
Once you step outside this logic, you can see the many contradictions and variances from reality. Eventually, you realize the Bible is not a valid basis for your beliefs - and there are NO other sources of that belief that DON'T derive from the Bible.
As to the difference between Theism and Atheism: They are different like black and white are different. Though both are possible perceptions, one is characterised by the total absence of light of ANY color (in the formal scientific sense of color) whereas the other is characterized by the presence of ALL colors in sufficient quantity and proportion that no color has preponderance of perception over another, but what you see won't be mis-recognized as black. Presence vs. Absence - the topic is the same but the results are very different.
IF you wish to quibble with me, remain within my definitions. If you wish to argue for the sake of argument, be my guest - but don't expect me to play your game by your rules if you won't play by mine.
Now, having taken a position on atheism, I'll take other positions. And DAMN the Aha's, full speed ahead.
While I'm certainly not aware of all details of the big bang and big bounce theories, they are at least reasonable to my way of thinking. The "Goddidit" method of creation is not at all reasonable to me because of my underlying lack of Faith in the existence of God. That level of physics isn't within my training, but to the extent that I understand all of the principles, I can accept the Big Bang/Bounce as possible.
Comments about "Physics started microseconds after the Big Bang" as stated by Mr. Hawking et al. are incorrect use of language, which any scientist or theist can do by being careless. My modification is "Physics as we know it started microseconds after the Big Bang." If there was a different type of physics, different laws, different conditions before that moment, we cannot decipher or decide what they might have been. Which is a far cry from saying "NOTHING preceded the Big Bang."
If an atheist says "We don't know how event X happened" then theists jump on our stuff. But if we question any theist about the inexplicable, they answer "God works in mysterious ways." Which is religious-speak for "We don't know how event X happened." So I'll point out that whether I believe in the Bang/Bounce idea or the FSM theory of creation or a Christian theory, I don't know that answer for certain. All I know is what I do or don't believe. I don't believe in the Creationist story or the FSM story. Hey, it's a position. You take your position, I'll take mine.
As to evolution by natural selection vs. evolution vs. natural selection, this is an apples and oranges argument semantically because one is a general statement and the other is a mechanism that might apply to or be subsumed within the general statement. So it is another example of careless use of language.
The line of thinking about the CAR and its beliefs isn't original. I came from Christian upbringing and reached my current position only after a long time. But I remember the scripture I studied as a much younger man. What usually gripes me about Christians is how they cherry-pick the Bible and then expect me to let them get away with it.
Does anyone recall the Biblical question about whether a stone could enter Heaven? The answer being that without making a choice, one cannot enter Heaven, and the stone is incapable of choice. So NO, a stone cannot enter Heaven.
Condemn me, praise me, or ignore me, but at least recognize that I have made my choices and made them as clear as my use of language allows.
Pardon me while I put on my bullet-proof vest and other protective gear for the pot-shots that so often come my way when I take this attitude. As if I cared.