Words like “atheism” or “agnostic” make sense as shorthands for everyday conversations or labelling, but if you want to be rigorous about it, it makes more sense to use 4 categories:

• Gnostic theist: I know there’s a God, I’ve met Him, I feel it, I have faith, etc.

• Agnostic theist: I don’t know if there’s a god or not, but I prefer to believe there’s one

• Agnostic atheist: if we don’t know if there’s a god or not, there’s no reason to believe there’s one. Do you assume there’s an invisible giant teapot orbiting Earth because there’s no proof to the contrary?

• Gnostic atheist: a god can’t possibly exist, the concept of a god is illogical, etc.

I’m agnostic atheist, but maybe there could a firm reasoning for the gnostic atheist position. I don’t know, I would have to read and think about it more.