I've come to believe calling oneself an agnostic about God is, in the vast majority of cases, a double standard revealing flawed assumptions and socialized pressures. I don't blame anyone for struggling with those pressures, as I still do and still will even after posting this.
Throughout my life, I went from Jewish to Monotheistic to Deistic to Agnostic to Atheist, with occasional skips and hops back and forth between the last three, sometimes as fluidly as all within the same day.
Why? A number of reasons. I liked the idea of a sentient Higher Power looking out for humanity, disliked the idea that there's nothing for me after death, and sometimes think that humans are so remarkable, the richness and variety of our life so wide, that surely some Celestial Spark must have been placed in one of our ancestors sometimes in the past 10,000 years or so.
But while I can't help occasionally feeling those things, rationally there's just nothing left for me to hold on to: no arguments, no evidence, no matter how much I look and read and listen and debate.
Atheism is a "dirty word" in much of US society, and only exists because the majority of people are theists. No one calls themselves an a-astrologist, because most people don't seriously believe in astrology. But because the default for religion is flipped to "on" thanks to a world full of childhood religious indoctrination, we who left the fold must loosely label ourselves by the absence of a belief.
So why can't I call myself an agnostic anymore? It's nice and safe and inoffensive, isn't it? Atheism is just "so arrogant!"
Well, here's the thing. Most agnostics say that their belief that God may exist boils down to a) the lack of evidence He doesn't exist, or b) the inherit mysteries of the universe. Not just that we don't know everything, but that He's potentially unverifiable, and therefor outside the purview of science or reason.
The problem is, this can apply just as well to anything magical or mystical.
Do I believe in magic? Primal spirits, like the life force of rocks/animals/the planet? Unicorns? Ghosts? These are things that may well exist outside our ability to observe/detect/test, just like God. I used to believe in many of these things, and am still open to the idea that they might exist.
But do I call myself an agnostic on those things? If someone asks me if they're true, do I say "I don't know, there isn't enough evidence one way or the other?"
Most likely, no. Most people don't, in fact. If pressed I'll say I'm OPEN to the belief in them, but until evidence shows up I disbelieve.
This is exactly what the vast majority of atheists say about God.
To claim that "asserting with 100% surety that there is no God is just as arrogant as claiming with 100% certainty that there is" is a strawman itself. The vast majority of atheists, even those as "militant" as Richard Dawkins, will readily admit that they are not 100% sure of God's lack of existence. Only 99.9%, or 9.7/10, or some such.
Acknowledging two things is important here:
It's as impossible to pretend to disbelieve something you believe as it is to pretend to believe something you disbelieve. Meaning you can't just through a matter of willpower believe you are a mosquito: on some level, you know that you really are not a mosquito.
It's impossible to prove an unverifiable negative. I know this comes up a lot, but only because it's a monumentally important logical fallacy that many people fail to check against every aspect of their worldview.
But due to the "Prove a Negative" fallacy inherent in the argument of agnosticism, to say I'm an agnostic and not an atheist is to say I believe that God is just as likely to exist as anything else I can't prove doesn't exist, such as unicorns, leprechauns, ghosts, etc. Which is why "agnostic deist" or "gnostic atheist" are actual things, much more precise than the shorthand many use.
And while some people may well admit being agnostic on all of those things, the vast majority I've met will say no, they don't believe in unicorns, but on the issue of God they are agnostic. Which leaves God as a double-standard born of societal pressures, because we've been conditioned to treat religious beliefs differently.
Final points:
I know rain is the result of precipitation. Can it be more than that? Are there undetectable rain spirits also affecting whether rain falls? Not likely, but I have no idea. Should I then say that rain spirits might exist, even though I have no evidence of it?
Being open minded means being open to the possibility, but being informed and rational means basing beliefs on probability. If someone asks me if I think dragons exist, I don't say "Maybe." I say no, I don't think so, because there's no evidence or logic to support it. That doesn't mean I think they can't exist. Why should it be different for God?
In summation, due to social stigma, "atheism" is seen as an extreme view rather than the rational starting point (disbelief) of any unverifiable claim. We are all born atheists, just as we are born a-astrologists. But we live in a time and place where it's deviant to disbelieve in one of those things, but not the other, on purely inconsistent rationale. And so, many people consider themselves agnostics, despite having just as little reason to believe in God as anything else they have no evidence of.
TL;DR: Under what criteria does a rational acknowledgement of lacking evidence support an unsupported theory?
Why should the perfectly reasonable "I don't know what the truth is," get the addendum "so maybe God?" rather than "maybe wizard?" What reason or evidence besides cultural influence do you have to believe God is just as likely as any other hundred magical things you don't believe in without evidence?
(As a final note, I am aware of the "agnostic as adjective" spectrum of belief. While technically correct, I don't find it particularly useful a labeling system. Anyone who is gnostic about the existence of God, a being that by definition is able to do anything they God-damn want, including evade any and all scrutiny by puny mortals, just isn't thinking clearly. So I consider almost everyone agnostic, even those who believe God exists with 100% purity, because they will quickly say "Oh, well science can't prove He exists," which means "nothing can" as far as I'm concerned. So I use "agnostic" as a noun, the way most people do, to identify their belief on God as being unsure/undecided.)
A simple definition of the two boils down to what do you believe and what do you know. Not sure the accuracy of the definition, but my take is atheist means I don't believe in gods, agnostic means that I don't know if there are gods (and perhaps due to my composition could never know).
In reality, I have found most agnostics are afraid to take a stand and say they don't believe in gods. They are a bit wishy-washy with the whole "Well, I just don't know, so I can't make a decision." Not saying all are like this, just the limited one's I have encountered and spoken too. I am agnostic when it comes to unicorns and leprechaun , in that yes, I don't know of any that exist, nor do I know if I will ever be able to know if they exist. Yet I have the courage to take that knowledge and form some assumptions that since I don't know of any, I infer (believe) they do not exist. Could I be wrong...absolutely. I am not so arrogant to think I have all the answers, but I am also no a coward to kowtow to public opinion and delusions by trying to stay on the fence with an "I don't know therefor I can't believe either way" excuse.
Honestly, I don't think it's typically enough of a difference of perspective to affect public policy, laws, and societal constructs in the majority of instances. Given that, I don't put too much effort into dissecting the nuances of the two.
No real reason to call oneself anything unless one needs a label in order to be recognised for doing something or bring someone..
I used to say agnostic to avoid arguments with theists. Then, I realized I was denying them the opportunity to meet and know an honest skeptic who challenges their notions of wanting to sin. I am not a militant evangelist, but I am out and happy to have a drink and talk with my religious friends who are "concerned"?
Reading through all these erudite discussions, I’ve been imagining Rene Descartes attempting to remove everything that is subjective, in order to figure out what’s real and provable, and what’s not...all he could come up with is “cogito ergo sum.” It’s like trying to achieve absolute zero temperature. You can get it to be damn cold, but as long as there is 1 atom still moving, there is heat. We all interact with existence as we experience it. If I don’t feel like enough atoms are moving, I say I’m cold. If I don’t see evidence of a deity, then I say there isn’t one. Sorry, Rene, I’m going to proceed through life as though there is no deity, whether I can prove it or not.
I do not believe in a "God" or "Gods" or heaven or hell.
And therefore, I'm an Atheist...
I perfer to call myself a naturalist or humanist, but if someone asks if I am an atheist I won't try to correct them or explain why the term is special. The term "atheist" has a reputation outside the secular comunity, and I'm ok with that. I'm perfectly fine with letting someone use the label as starting place to understand my point of view.
To me, an "Agnostic" is kind of like announcing that you have trouble committing and you still have foot caught in a pile of bibles.