According to

a·the·ism [ey-thee-iz-uhm]

1.the doctrine or belief that there is no god.
2.disbelief in the existence of a supreme being or beings.
A quote that sums it up perfectly:

I contend that we are both atheists. I just believe in one fewer god than you do. When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.
~ Stephen Roberts

And another:

Which is it, is man one of God’s blunders or is God one of man’s?
~ Nietzsche

I’ll leave it at that. You can form your own opinions.