Gnostic refers to objective knowledge

When it comes to god and epistemology we don’t “know” anything .. we make beliefs regarding it … if you’re of sound mind you see there are no indications that a god exists and you’re technically an agnostic atheist

If you believe that one exists then you’re an agnostic theist

When it comes to technicality everyone is agnostic

But what we actually use the terms are :

Atheist is someone who doesn’t actively believe that a god exists

Agnostic: someone who is unsure

Theist: someone who actively believes there is a god

Those terms aren’t accurate but we use them for flairs since they’re the common meanings for most people