What caused you to believe?
My thinking is that belief comes before reason. IOW if you believe in something enough you'll find a reason for continued belief. This is probably wrong as some atheist may have experienced something supernatural to cause belief.
Since I started life as a believer having experiences which provided reason for continue belief were common enough. Becoming an atheist, these experiences no longer occurred. Kind of like the Matrix, once you take the red pill, impossible to go back.
However I know there are ex-atheists. So did some supernatural event occur during your state of non-belief to cause belief or was it just a need for the support of a religious ideology/community.
This is a fantastic topic! I don't think I've seen anything like that here on RF, asking the way you are looking at the possible variables. I think there are more than a few of us here, and we all have our stories.
To answer this question for me, really is the whole book was working on at some point to finish. Maybe answering this here will spur me on further as a launching point. It's a book's worth of material and then some to begin to cover all of it. In short however.....
I didn't begin in religion. I began as some kid in an average middle-class American home where religion was really more peripheral, culture things like Christmas, Easter, and stuff. Just plain jane white bread cultural "Lutheran". No teachings about God in any "believe this" kind of way. Didn't really understand much of any of all what I had been exposed to around me culturally anyway. It seemed "suspect" to me, kind of foreign ideas as such. Probably why it wasn't taught in the home. My father was very much a rational person, business man, important roles, and such. He was cynical towards religion, my mother less so. Yet he was a quitely spiritual man, who saw life as full of beauty.
I think I just wrote the first paragraph of my book! Thanks.
I think from here the rest short history will make some sense. Fast forward, at 18 I had an Awakening experience, as I would later come to understand them. It was an Enlightenment experience which shattered reality open to me, as a young confused man facing an existential crisis of being. This came in two parts over the span of a week's time. It forever changed my life.
This left me in search of understanding this immediately after the experienced had gone. That search pointed me towards religion, which in my youthful naivety, eagerly took what I could find which offered anything remotely close to what that was. That got me thrown into religion for the first time. Did the whole thing, soaked it all up like dry sponge. Until that sponge got too full. That's when I left them.
I was too rational for that stuff I was being taught about God, this Ultimate Reality I had experienced. It not only did not match this "God" that I experienced, throwing people into a hell I knew in my own experience was impossible to even exist as God is Absolute Love. It also didn't stand up to reason! It was all a house of cards fumbled together to stand in a certain order by them and then deemed "the truth".
So, given that I had already quickly outgrown the spiritual clothes they offered for me to wear as part of their church, it didn't take too much examination of them with the eye of reason to give me the justification to make my exit from their ranks, on search of a new horizon of truth to explore, sans them. That took me into a wasteland. Other churches had even less to offer.
This wasteland period found me giving up on religion and going it alone, without finding anything that could offer any meaning to my experience, or possible direction to follow. Then one day, I had a new "awakening" experience of sorts that led me to take that "idea" of God the church I was in and kick it off the throne. It was an intellectual "ah hah" type moment. Evolution doesn't require that kind of God to exist, as they had tried to tell me what God was. (It caused a lot of conflict for me).
So with that gone, I now was free from the Old Testament deity that I tried to recognize in my experience (very little in fact). But now that was gone, on with dissecting the rest. The whole thing about religion, and the Bible, it's history, all the critical analysis, all the modern scholars, understanding science, anthropology, ethnology, linguists, semiotics, philosophy and so forth.
I proudly debunked all the literalism I had be handed during those days. My rational mind which saved me from truly becoming them, now made me a sharp edge against which I could slice through them deftly, surgically. For ten years I moderated at an atheist cite and was a champion to the cause for many with my rational mind and knowledge being as it is.
But, yet, in all of this, there was that spiritual side that could not be denied for too long. That was very real, and in fact is the very core of who I have been ever since that experience at 18. As a gust of wind would come up to me and I felt my soul move out into the universe, this seemed a rather hypocritical thing for an atheist to admit publicly. It was the experience of God, and yet I didn't believe in that God anymore.
Fast forward again, keeping reading, keeping searching, postmodernism, and into post-postmodernism. Enter in meditation practice.
Then I began where I began at 18, decades now later. It immediately opened me to what I had experience at 18 again, picking up right there, before the onset of religion and it's resultant atheism. What had started as an atheist for me to find the search for the Holy Grail, a way to bring faith and reason together, to bring spiritual experience and the rational mind together, had in fact been found. It is in transcending them both, as they are really the same thing. Just different eyes on the same Face. Each eye informs the other without needing to lie. Each grows from each other.
So atheism is something that is very much a part of me, as it denies the mythical which seeks to deny the rational. But it fails to be rational enough, to the point it sees its own inherent irrationality. If fails to offer an understanding of the spiritual that registers both spiritual and rationally. When it doesn't outright dismiss the spiritual as "woo", it intellectualizes it away as "just the brain" or something. That's not satisfying to me on every level. So my body outgrew those clothes as well.
That's where my search took me to, the limits of the rational to be able speak adequate to the Whole which embraces the rational and the spiritual as inseparable. It's going beyond the rational, going beyond theism and it's offshoot atheism. It denies nothing, and embraces everything.