There is a huge difference between someone arguing for atheist and someone arguing for religion, and that is one is right and one is wrong. It is the same difference between someone arguing over if the earth is round or flat. Atheism doesn't require any faith and we can easily 100% prove all religions are wrong.

The difference between and agnostic and atheist is pretty much meaningless in most conversations. Most agnostics know all earthly religions are false, and they know there is absolutely no reason to believe in a god but they want to be intellectually honest and so admit that there is an infinitesimally small chance that anything could happen. I personally don't see the point in doing that, since there is no practical reason for it.

If I am talking to someone about gravity, and say if you drop something it will always fall because of it, there is some tiny small chance gravity might not work one day and the object will not fall. However there is no practical reason to say that, and so anyone talking about it will just says that object falls towards earth due to gravity. In the same way there is no practical reason to talk about infinitesimally small chances of there being some vague concept of god around, you can just simply say, no he doesn't exit.

So I just call myself an atheist. We know for a fact that all current religions are man made and are thus untrue, and a god doesn't really make sense in in universe due to the laws of physics, so we can safely say there is no god and leave it at that.