Agnostics are the most intellectually honest of non-believers. They admit they don’t know one way or the other, or care. No evidence either way.

Atheists reject the thought of a GOD because it would mandate a change in their behavior and values they are not willing to do. So they forcefully reject the notion, which actually requires as much faith as the believer, because they also have no proof. In fact, the motion of the universe, stars, and all therein implies a creator put it in motion. (Nothing logically moves itself, or creates itself.) So they are denying the laws of the universe we have all observed over time.