I found the following posted in the comment section of a Capturing Christianity’s YouTube “Community” post, by a user who goes by the name “Theo Skeptomai.” I think it’s well written, and does a good job of articulating why this person is not a theist.
Hello. I am an atheist. I define atheism as suspending acknowledgement of the existence of gods until sufficient evidence can be presented. My position is that I have no good reason to acknowledge the existence of gods.
And here is the evidence as to why I currently hold to such a position.
1. I personally have never observed a god.
2. I have never encountered a person whom has claimed to have observed a god.
3. I know of no accounts of persons claiming to have observed a god that were willing or able to demonstrate or verify their observation for authenticity, accuracy, or validity.
4. I have never been presented a valid logical argument which also employed sound premises that lead deductively to a conclusion that a god(s) exists.
5. Of the 46 logical syllogisms I have encountered arguing for the existence of a god(s), I have found all to contain multiple fallacious or unsubstantiated premises.
6. I have never observed a phenomenon in which the existence of a god was a necessary antecedent for the known or probable explanation for the causation of that phenomenon.
7. Several proposed (and generally accepted) explanations for observable phenomena that were previously based on the agency of a god(s), have subsequently been replaced with rational, natural explanations, each substantiated with evidence that excluded the agency of a god(s). I have never encountered vice versa.
8. I have never experienced the presence of a god through intercession of angels, divine revelation, the miraculous act of divinity, or any occurrence of a supernatural event.
9. Every phenomena that I have ever observed has emerged from necessary and sufficient antecedents over time without exception. In other words, I have never observed a phenomenon (entity, process, object, event, process, substance, system, or being) that was created ex nihilo – that is instantaneously came into existence by the solitary volition of a deity.
10. All claims of a supernatural or divine nature that I have encountered have either been refuted to my satisfaction, or do not present as falsifiable.
ALL of these facts lead me to the only rational conclusion that concurs with the realities I have been presented – and that is the fact that there is no good reason for me to acknowledge the existence of a god.
I have heard often that atheism is the denial of the Abrahamic god. But denial is the active rejection of a substantiated fact once credible evidence has been presented. Atheism is simply withholding such acknowledgement until sufficient credible evidence is introduced. It is natural, rational, and prudent to be skeptical of unsubstatiated [sic] claims, especially extraordinary ones.