I am an atheist. The philosophy of reality I embrace is called Existentialism. Hardly a paradox and certainly not uncommon.
Existentialism has its flaws.
One of the founding ministers at our church once said that every atheist can give you a detailed description of the God in which he does not believe. (Sometimes much more detailed than the believer can.)
I got in an online discussion with a group of atheists once. One of them PMd me, and I urged him to consider a much broader perspective of a universal God, immanent and transcendent, operating as and through everyone and everything. He rejected it because “I could believe in that and I don’t believe in God.” Therefore, in his worldview, that could not be correct.
OTOH, a high school classmate of mine (we were in the same graduating class) wrote a book called An Atheist Defends Religion, which is a fascinating read.