Apparently if your assertions about yourself are true then you are an agnostic not an atheist (though atheists today like to jumble these together in our time, having been shown the total lack of rational support for their position). So the next step would be to get you to admit to yourself that the reality is more than merely materialistic.
I'm and agnostic atheist. Agnostic is a knowledge statement, and atheist is a belief statement. As an atheist, I lack any belief in deities, and as an agnostic, I don't know for sure if deities exist or not. My position is a matter of a lack of evidence for the existence of deities, not presence of evidence that they don't exist. Most atheists are agnostic, people just choose to call themselves agnostic when they want to avoid the stigma of the atheist label (or when they incorrectly think that being agnostic is a more mild position somehow). Furthermore, a person can be an agnostic theist as well.
DO you agree there may be other non-material aspects of reality (other simultaneous realms, other 'only experience-able' aspects, areas only discerned intuitively, the nature of the role one's limited ability to perceive plays, where others may not be so limited, and so on)?
Sure. Ghosts may walk through my body on a daily basis and, since they can't be detected, and I'd never know it. However, any experience that I would be capable of detecting should be measurable in some way, otherwise there's no means of distinguishing such an experience from a hallucination or a dream. Basically, such personal experiences might convince me that the subject in question exists, but it would be unreasonable to expect other people to take me for my word alone.
I'm sure that schizophrenic people experience plenty that I wouldn't be able to perceive. Funny thing, though, using brain scans, you can actually tell if people are experiencing something that you personally aren't. However, it helps me none since that doesn't demonstrate that what they are experiencing is or isn't the result of their own imagination or mental illness.
For example, it appears that all peoples in general (not every individual), of varying genders, ages, educations, and social status, throughout all time have recognized, or experienced (some even visually or audibly) the aspect of reality they may refer to as the "spiritual" realm.
Ever note the lack of consistency in their descriptions of it, and that it is culturally guided (these people don't see anything they haven't already heard of before)? Also, tons of frauds exist.
Now granted each culture over time has developed their own interpretation of what realization they perceived and developed their own cult of ritual regarding this realization. However, that it is (sometimes essential) and always has been part of what separates humans from beasts (not discounting the animal nature of our bodies).
Ha, there's no reason to assume that "spirituality" is human exclusive. Chimps and other apes do grieve, and some people think cats and dogs sense spirits better than humans can, etc.
Furthermore, there's no reason to assume that spirituality has always been a part of human culture. Not that it would lend it any legitimacy if it was. Plenty of fallacies and cognitive flaws have been long standing in our species, like perceiving this as a face
https://am23.akamaized.net/tms/cnt/uploads/2011/02/faces_happycoffee.jpg
Some of these flaws are a consistent part of our brain chemistry and function to the point that even actively trying to prevent them is prone to fail. That in no way makes that coffee have a face, or legitimizes any of the other erroneous things we come up with.