Apart, of course, from the obvious example of believing the evidence-free assertion of the Governing Body to be God's representatives on earth. Not to side-step that issue, but I wonder if it might be interesting to relate that huge mistake to other things I've been wrong about and how they compare and contrast with the big one.
A couple of examples of things I was wrong about:
1. In about 2007/8 I read a lot about "peak oil" and was totally convinced the end of the oil age was imminent. The evidence seemed pretty clear, with all the graphs, statistics, and examples from history. I couldn't think of any way it could be wrong. Yet it came to nothing, as far as I can tell. Oil and carbon seem to be as abundant (and cheap) as ever and no one talks about peak oil any more.
2. In 2016 I was convinced my vote to "leave" the EU was totally harmless. I believed this because: 1) I was sure "remain" was going to win anyway 2) voting "leave" was calculated to help the cause of Scottish independence which was a greater priority (complicated reasons) and 3) even if it did happen it wouldn't be the end of the world and might just shake things up a bit. Well how wrong could I be? Firstly, shock horror, "leave" did win. Secondly voting "remain" would have been a better strategy to further independence, it turns out. And arguably the "leave" vote led to a sequence of events that put Trump in power, threatening the future of civilisation itself. Oops.
All sorts of self delusion involved there. In the first instance I paid to much attention to books and YouTube videos promoting a particular view without considering the other side. In the second case I paid to much attention to the media that said "remain" was going to win and didn't take the vote seriously enough,
I wonder what other things I currently believe that will turn out to be wrong. I guess I hold "minority" opinions on various subjects that could turn out to be wrong:
1. I believe the New Testament originally contained the divine name.
2. I believe the "singularitarian" view of the future taken over by strong artificial intelligence is probably correct.
3. I believe the classical secularisation thesis is correct. (Although pretty redundant, now I think about it, in view of no. 2 above)
4. I believe the distinction between conscious and unconscious matter is problematic and there are problems with materialist conceptions of reality generally.
5. I believe it's more likely Trump will either be removed from office or will start a world war than that he will reach the end of his term with the planet intact.
Is anyone else willing to share, either things you were convinced were correct, but turned out to be wrong, or minority views you currently hold that may turn out to be incorrect?