The terms "theist", "agnostic", "atheist", and "spiritual" are too often misrepresented by innacurate definitions. I recommend the use of Richard Dawkin's theism scale to help standardize their meanings, with a couple of tweaks and additions. Some basic rules of logic:
So, the scale from theist to atheist is as follows:
- Believing in something does not require any proof or evidence.
- Knowing, or stating something as fact requires proof that can be substantiated with evidence, logic, and reason.
- The burden of proof is on the claimant who states that something exists.
- Following #3, it is illogical to try and prove something does not exist.
- Lack of evidence doesn't mean something doesn't exist, though it can lead to that conclusion for practical purposes.
* - The God of Christianity (Christians), Judaism (Jews), and Islam (Muslims).
- Strong theist. In the words of C.G. Jung: "I do not believe, I know."
- De facto theist. Very high probability. "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. "I am very uncertain, but I am inclined to believe in God."
- De facto agnostic. Completely impartial. "God's existence or non-existence cannot be known."
- Agnostic athiest. Leaning towards atheism. "I do not know whether God exists but I'm inclined to be skeptical."
- De facto atheist, or non-theist. Very low probability. "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."
- Anti-theist. "I know there is no God, and will aggressively argue my point."
- Spiritual. Prepend all the above terms with "Spiritual", then add this to the description: "And I believe that everything in the universe is in some way connected."
The most important ones to differentiate are numbers 6 & 7. Some think that all atheists makes the statement "There is no God". Well, some do, some don't. Stating "I do not believe in God" or "I do not believe there is a God" is more like #6; a slightly less strident statement. Many atheists I know will say they are 99.9% sure there is no God (placing at #6) for the simple reason that it is logically fallacious to prove a negative; to try and prove something does not exist beyond all doubt is impossible.