I once was mistaken about the meaning atheism, and I have encountered many others who are also mistaken about its definition, so I’d like to clarify.
Theism is the belief that some God or Gods exist.
Atheism simply lacks that belief.
Now, many people wrongly take this as, “Atheists believe no God exists.”
While there are some atheists who fall into this category, the additional belief that no Gods exist is not a requirement of atheism.
I think people have a difficult time understanding the difference between,
“Does not believe in God,” and “Believes that no God exists.”
Agnosticism is often described as the middle ground between
theism and atheism. But there is no middle ground.
Either you believe in a God or Gods, or you do not believe.
Agnosticism is a belief about knowledge, that we do not or cannot know.
A person can believe that they do not know, but still have faith in God, and likewise, a person can disbelieve in God(s), but still not know, to an absolute degree,
whether or not a God, or Gods actually exists.
Agnosticism is therefor irrelevant to whether or not a person believes in a God or Gods.
I hope this was helpful.