Gnostic / Agnostic is simply a claim about knowledge.

I am agnostic as to whether my bread is stale. (I don’t know if my bread is stale).

I’m gnostic about the planets shape (I know it’s a dodecahedron).

Theist / Atheist is a claim about belief.

Every person fits into one of the following:

• A Gnostic Theist claims to know God exists (therefore implicitly believing)

• A Gnostic Atheist claims to know God doesn’t exist.

• An Agnostic Theist believes in God but doesn’t have sufficient evidence to make definitive claims.

• An Agnostic Atheist doesn’t have sufficient evidence to make claims about God, and therefore doesn’t believe.

In terms of rationale, both Gnostic groups make definitive claims without sufficient evidence and should not be trusted.

The Gnostic Theists believe in something without evidence, this is a fallacy, but it’s something we all do every day. For example, I don’t know if it will rain, but I believe it might, so I bring an umbrella.

An Agnostic Atheist is the most rational. If you don’t have sufficient evidence to make a definitive claim, then why would you believe it?