I think many of my theistic beliefs are adapted to argue for a conscious, biblical God. I don't find those arguments persuasive, but they do have the same starting point.
So what is the "starting point"? What is the first thing you must believe about God in order to be a theist (other than the obvious "He exists")? That He is good? That He is the creator? That he is in control? Or is it just a vague feeling that "there must be something more"?
Well, I personally think the term is useful. Remember, this belief accepts the possibility of a conscious god equally with the possibility of a random first cause. This is precious close to agnosticism, I suppose.
It is indeed close to agnosticism. And it still sounds to me as if you are allowing one definition of "God" to be "something I have no information about whatsoever." That doesn't seem like a very useful term to me. More like a placeholder.
Where my belief system splits off from agnosticism is that it examines what man's relationship is with god if it is a conscious or semi-conscious entity, as well as if it is a random first cause. I believe that traditional agnosticism does not do this.
I'm really not sure what sorts of beliefs about God are mandated by agnosticism. I find (from cj.23 -thanks!

) that my concept of gnosticism is different from the philosophical one. But I don't think agnostics, as I understand them, believe that man has any relationship with God, since they don't know whether or not He exists. But you may be talking about their relationship with the
concept of God, so I don't want to put words in your mouth. You'll just have to explain what you think man's relationship to God is. We don't have to give it an "ism". Forcing things into artificial categories has never been conducive to understanding, in my experience.
I don't think they universally make other claims. My belief system does not, and I've talked with a number of folks who do not seem to.
Perhaps "claim" was the wrong word. Theists believe in
something they call God. For them to believe in it, then they
must have some definition of God that they find acceptable. Atheists need not have a definition of "no god". They can examine your definition and many other definitions and decide whether or not they believe in them.
But when we get into pantheistic definitions of God, then weirdness ensues. Take this scenario:
Atheist: I have never heard of any concept of God that I believe in.
Pantheist: I believe God is nature.
Atheist: I don't believe God is nature.
Pantheist: You don't believe in nature?
Atheist: Of course I believe in nature, I just don't believe it is God.
Pantheist: Well it is MY God, so you must have some kind of other God that you believe in that you are comparing to MY God.
Atheist: No. I have not found ANY gods I believe in.
Pantheist: Don't you believe in nature?
Atheist: Arrrrrrghhhh!
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You can see that simply defining God as something that has another definition is not really a definition of God. It is simply substituting "God" for another word. Suppose you decided to call trees wombats? If you told somebody, "I want a house near the woods because I love to sit under a shady wombat," then that person would rightfully look at you like you were crazy. They might do so even after you explained that you called trees "wombats".
I'm sorry if anything in this thread was insulting to atheists. I don't think that was the intention of anyone here.
I know it wasn't, and I wasn't at all insulted, but one of the things that most people of any persuasion find annoying is to have their beliefs defined wrongly by someone else. I know Christians get annoyed when somebody says, "So you're a Christian? That must mean you hate gays, right?" It is equally annoying to an atheist to be asked, "Why do you hate god?"
That is why most people here work very hard to eliminate strawmen.
Does that make the atheist position essentially agnostic?
As discussed below, there is a lot of overlap. By my definitions, it is possible, even likely, that most atheists are also agnostic. That's why we have to make sure people know what we mean when we use the words.