Now Richard Dawkins has what he calls the "Spectrum of Theistic Probability". It is broken down like this (taken from Wikipedia):
- Strong theist. 100 per cent probability of God. In the words of C.G. Jung: "I do not believe, I know."
- De facto theist. Very high probability but short of 100 per cent. "I don't know for certain, but I strongly believe in God and live my life on the assumption that he is there."
- Leaning towards theism. Higher than 50 per cent but not very high. "I am very uncertain, but I am inclined to believe in God."
- Completely impartial. Exactly 50 per cent. "God's existence and non-existence are exactly equiprobable."
- Leaning towards Agnosticism. Lower than 50 per cent but not very low. "I do not know whether God exists but I'm inclined to be skeptical."
- De facto atheist. Very low probability, but short of zero. "I don't know for certain but I think God is very improbable, and I live my life on the assumption that he is not there."
- Strong atheist. "I know there is no God, with the same conviction as Jung knows there is one."
I would like to touch briefly on Gnosticism as well. Gnostic, as defined by dictionary.com, is 1. pertaining to knowledge or 2. possessing knowledge, especially esoteric knowledge of spiritual matters. So basically what we're talking about here is knowledge, not belief. I would also like to point out that knowledge is a subset of belief, however that's irrelevant to my point. My point is a gnostic theist is someone who not only believes there is a god, but knows there is. A gnostic atheist would be someone who knows there is no god (or a strong atheist on the spectrum of probability outlined above). Most rational, logical thinking people will lean towards taking an agnostic approach to the question of theism. I've often heard theists argue to me that they don't need proof of gods existence to believe in him, they simply have to have faith. This in a way is them admitting that there is no proof and therefore they don't know for certain that he exists. So it is possible for someone to believe in god and still be agnostic.
I'd like to wrap this up by stating that in all honestly I hate labels regardless of what it is you are trying to define. I take them with a grain of salt. I believe you should too. Think of it merely as a quick and simple definition to a much larger, more complicated principle. Your idea of what defines an atheist might be slightly different than mine. But if someone asks you if you are an atheist are you going to say no and then proceed to describe what it is you actually believe? It's just an easier way to sum up your beliefs. Whenever I get into a discussion with someone of religious faith I first take the time to find out what it is they actually believe. It's important to know where they stand on certain things. I can't simply just say to someone "Oh, you believe in god. So how silly you are to believe the earth is only 6,000 years old." Well, the fact of the matter is they might not actually believe that. In conclusion, do not be so quick to judge someone simply because of their beliefs or lack thereof. Especially take the time to find out what it is a person believes and why it is they believe that. You will be surprised at what you learn and if you keep an open mind you just might change yours.