Believers refuse to give God a real definition because then it would be falisfiable. They insist on defining it as unknowable because then it is unassailable. Their belief is based on nothing but faith. It is not at all true that atheism must be based on the same sort of faith. There is no reason to believe that God is the wind or a force of nature or any of the other mythological nonsense and fairy tales that are the basis of religion. One need not employ faith to reject the argument from ignorance.
I agree, faith is not needed to reject it. I was just pointing out that whether or not a god hypothesis can be proven or not depends on how you define that god. Some gods could be falsified, others not.
Example 1: The idea of an "all good" and "all powerful" god makes that god logically inconsistent in a world where evil exists. That god can not exist.
Example 2: "God is everything". That definition of god is too nebulous and isn't even really defined. By saying that god is everything you're saying he's nothing.
Example 3: "God is the thing that created the universe." We don't know yet what created the universe and it may be unknowable. As such, that God can't be falsified.
Depending on which god hypothesis you give will depend on which type of atheist I am towards it.
To most god claims I'm an "agnostic atheist" meaning, I don't know if that god exists, but I don't believe in it"
To some, like examples 1 and 2, I'm a "gnostic atheist" meaning, I know that god doesn't exist, and I don't believe in it."
Religious people can use the agnostic/gnostic qualifier too. Some claim to "know there is a god and believe in it" (gnostic theist) and some claim not to know there is a god, but still believe there is one (agnostic theist).
My main thrust was that falsifiability depends on the definition of the god claim.