Greek mythology. I never believed any of these myths. That is, I recognized that they were myths and that they reflected beliefs that had long-since vanished. At the time, I saw my Christian beliefs as being very different. But while my familiarity with these ancient Greek myths had little impact on my acceptance of contemporary Christian beliefs at that time, this would eventually change.
If someone had sat me down as a child and pushed me to explain the difference between ancient Greek myths and the contemporary Christian beliefs which I still thought were true, I am not sure what I would have said. I would have claimed that the Christian beliefs were true, of course, but I am not sure what I would have said if pushed to explain how I knew this to be the case. I probably would have relied on very primitive and uninformed versions of the same arguments we hear from Christians today. I probably would have dismissed the Greek myths as being too old to be relevant, and I imagine that I would have noted that nobody still believes them. I might have contrast this with the popularity of Christianity in the United States today. I would not have recognized why this line of argument was so seriously flawed.
I also would not have recognized that what I was essentially arguing was based on familiarity. That is, I would have been insisting that the Greek myths seem silly while the Christian doctrine makes more sense, and I would have been doing so without realizing that this difference came down to my familiarity with the Christian beliefs. It never would have occurred to me that Christian doctrine would seem far less normal if I had grown up in a different part of the world.
Within a few years, I'd begin to question much of what I had been taught about Christianity. All of the sudden, those ancient Greek myths came roaring back with a new relevance. Why was it any more likely that there was one god vs. multiple gods? Wasn't the idea of many different gods far more interesting, and wasn't there the same evidence (i.e., none whatsoever) supporting their existence? Did the ancient Greeks believe in their gods with similar conviction as modern Christians believe in theirs? If the Greek dogs are now widely recognized as myths, couldn't the same thing happen to the Christian god and most of the rest of Christianity?
I found myself imagining how my Christian beliefs would be regarded by future generations. Perhaps there would be some who stubbornly persisted in observing them out of an odd sense of tradition, but most would probably regard them as myths. And with the passage of additional time, it would be harder and harder to find anyone who took them as anything other than myths.
I continued to cling to my Christians beliefs to the degree that I could, but it soon became impossible to do so. If I was honest with myself, I had to admit that there was no difference between my Christian beliefs and primitive myths. I had to recognize that what I had been believing about gods was no more likely to be true than what ancient societies had believed about gods.
Myths, whether they come from ancient Greece or the not-so-ancient United States, are still myths. They are interesting, entertaining, and often very revealing about the people who hold them and their cultural context. And yet, none of this means that they correspond to reality in any meaningful way. It would take evidence to do that, and evidence has been absent.