Darth Dane

Theist:

1) a : of or relating to theism
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2) n : one who believes in the existence of a god or gods


Atheist:

1) a : related to or characterized by or given to atheism
Example: atheist leanings
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2) n : someone who denies the existence of god


So a Theist is someone who believes a god or gods exist.

What do you call someone who knows god exist?

Gnostic:

1) a : of or relating to Gnosticism
Example: Gnostic writings
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2) n : an advocate of gnosticism
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3) a : possessing intellectual or esoteric knowledge of spiritual things

So a Gnostic isn't one who knows god exis, it is one having knowledge about spiritual things.



Is "gnostic" freely used as to those who knows God Is?


Agnostic:

1) a : uncertain of all claims to knowledge
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2) n : a person who doubts truth of religion


Would an agnostic know if they are uncertain?

Pyrrho

I think you would be well advised to consult a dictionary for the various terms you define, and give up on finding THE definition of a term, as most terms have a variety of related meanings. (Many people here seem to imagine that words have one precise meaning, which, in fact, every sensible person knows is false. But don't take my word for it; consult ANY standard dictionary to see for yourself [and also consider how people you have encountered actually use terms somewhat differently from each other].) You might want to look at both a standard dictionary and one made for philosophy; here is an online standard dictionary:

http://dictionary.reference.com/

As for "knowledge", some philosophers use that to mean "justified true belief", where "justified" essentially means "supported by evidence", clearly better evidence than any alternate position. With such a definition, I would say that it is impossible for anyone to know that God exists, since God doesn't, and there isn't any justification for the belief, as defined above.

Ottman Out

Gnostic is not the opposite of agnostic. The Gnostics were sects of the early Christian Church whose beliefs were eventually declared heretical. Try googling "Christian heresies gnosticism". The first one in the list, here, is a very readable history and description of Gnosticism. There is also what appears to be a home page for modern adherents of Gnosticism.

Ottman Out

Of course, we all know that an atheist is someone who lacks a belief in any god. But the philosophy dictionaries do not necessarily agree. For instance, Dictionary of Philosophy, by Peter Angeles, 1981: "atheism. 1. The belief that gods do not, or God does not, exist. 2. The disbelief in any kind of supernatural existence that is supposed to affect the universe. 3. The lack of belief in a particular God. (The Greeks called the Christians atheists for not believing in their gods and the Christians called the Greeks atheists for not believing in their God.)"