You are wrong.
Atheism vs. theism is a statement of belief - atheism is not believing in a god, and theism is believing in one.
Agnosticism vs. gnosticism is a statement of knowledge - being agnostic means you do not think it can be known whether or not God exists, and being gnostic means you think it can be known.
Atheism vs. theism is a statement of belief - atheism is not believing in a god, and theism is believing in one.
Agnosticism vs. gnosticism is a statement of knowledge - being agnostic means you do not think it can be known whether or not God exists, and being gnostic means you think it can be known.