I have had a few questions regarding my agnosticism and atheism from some Christian and non-Christian commenters, so I thought I would explain my position with an analogy between gods and aliens to demonstrate not believing versus believing not. I hope the three in the morning post doesn't lose its coherency...
I am an atheist because I don't believe in any gods. That is not to say that I believe there are no gods, just that I don't actively hold some belief regarding it. To assign some values to it:
+1: I believe there is at least one god. (theism)
0: I do not believe there are any gods. (a-theism)
-1: I believe there are no gods. (anti-theism)
The proposition is "A god exists." With that scoring method, I gain 0 points. Perhaps to make this more clear, let's relate this to aliens. We have the following scoring options:
+1: I believe that aliens exist. (alienism)
0: I do not believe any aliens exist. (an-alienism)
-1: I believe no aliens exist. (anti-alienism)
The proposition is "Aliens exist." Again, for this, I score a 0. It's not that I believe no aliens exist, it's that I have no belief regarding it. There may be or there may not be; I have no belief either way (I'll clarify this point later).
Just like with the god question, "alien" is not well defined. What are we talking about here? Super intelligent aliens? Semi intelligent aliens? Aliens constructing spacecrafts? Aliens who are mere life and not even sentient? It's as ill-defined as "god." What are we talking about here? An omnipotent, omnibenevolent, omniscient god? A deistic sort of god? A personal god? A semi-powerful god? An omnipresent god? It's not really defined.
Now, my lack of belief in aliens is not simply because I do not know. You can start defining the aliens and giving them characteristics. For example: A race of aliens who are super intelligent, capable of interstellar travel, and have been visiting Earth for centuries. They are little green men, with antennas coming out of their heads, they have been abducting people for centuries, probing them, and studying them. Once they have finished, they put that person back on Earth. That's the proposition, here's the scoring:
+1: I believe these aliens exist. (abductionist)
0: I don't believe these aliens exist. (an-abductionist)
-1: I believe these aliens don't exist. (anti-abductionist)
In this case, I score a -1 because I have the belief that these aliens with these activities don't exist. Of course, I don't "absolutely know" one way or the other; they may exist. I believe they don't, though. There are many reasons that have led me to this belief: Why always abduct the stupid people? Why the homosexual overtones with the abductions? Why travel all this way for all these centuries just to study us? Why not make your presence known? Why haven't we been able to detect you?
Just because I believe these aliens don't exist does not contribute at all to the general existence of aliens or to my general not believing in aliens. In other words, my anti-abductionist belief has nothing to do with my an-alienist lack of belief.
Now, to relate this to the god question. Start defining one and I'll see what I score on it. Take the Judeo-Christian God. He created the life, the universe, Earth, and everything 6,000 years ago. He's omnipotent, omnibenevolent, omniscient, omnipresent, etc. He had a son 2,000 years ago and wrote a book in his free time. He will judge everyone after they die and send them either to Hell or to Heaven, depending if they believed in the divinity of Jesus. That's the basic proposition, and here's the scoring:
+1: I believe this god exists. (Christian)
0: I don't believe this god exists. (a-Christian)
-1: I believe this god does not exist. (anti-Christian)
I score a -1 because I believe this god does not exist. Of course, I don't "absolutely know" one way or the other; he may exist. I believe he doesn't, though. There are many reasons leading to this belief: The contradictions of his magical power (omnipotence and omniscience, for example). The extraordinary amount of suffering in this world does not lead to an all-loving god. The idea that God exists, powerful enough to reveal himself, cares that we believe he exists, and does not show himself because he doesn't want to force the belief or whatever, is absurd. Why would a god that powerful even care enough to create us, and further would even care about us, and finally would care that we believe he exists? Why if it's all about us did he create the billions of others stars and planets? What about all the evidence which disproves the 6,000 year old Earth/universe? What of all the errors, idiocies, and immorality in the Bible? Why write a Bible at all? If he doesn't want to interfere with us, why do it once with the Bible and again with Jesus, but never again? Why isn't there more evidence regarding Jesus and why isn't there any about his magical powers? I could go on, but that's the point of the religious absurdity series.
My believing that Christianity is false (and, by consequence, the Christian God) has nothing to do with my atheism on the broader question of the existence of gods.
Is this all some grand equivocation to get around saying that "I believe that no gods exist"? No, of course not, as I don't believe that. I believe that certain proposed gods, such as Yahweh, Allah, Thor, Zeus, Anubis, Ra, Osiris, Apophis, Odin, etc, do not exist. Certain types of gods though, like a deistic type of god or even a god very limited in power and with no other defined attributes, I hold no belief in either way. I may one day believe in them, but the time to believe in something is when there is some good evidence or some good reason to believe in them. In the light of counter evidence, contradictions, and good reason not to believe, that is an appropriate time to believe they do not exist. And just like super intelligent aliens abducting the dumbest people on the Earth and having homosexual encounters with them, there is good reason to believe that Yahweh does not exist.
While not concise, I hope this elaboration was clear enough for those who have asked about it.