The entire community of "atheists" who are telling you this definition is true are talking nonsense. They are either ignorant of what atheism means, or they have succumbed to convenience over rationality.
Can you tell me why, when someone's view is covered by agnosticism, they want to label themselves and others as atheists?
Can you tell me why, when someone's view is covered by agnosticism, they want to label themselves and others as atheists?