@Olivier5,
Yes, I was pointing out that the word "theory" is used differently in the vernacular than in the scientific context. Since this thread is about science, seems it would be better to stick to the definition used in science in order to avoid ambiguities.
I was reading recently where someone hypothesized that people engage in denialism for emotional reasons and suspend reasoning in those special areas where reasoning leads to uncomfortable conclusions. A person might not be able or willing to analyze religious/magical thinking objectively because, for example, it challenges cherished family traditions or social identity. Rejecting religion might feel like rejecting loved ones who are believers.
Or it might lead them to confront the inevitability of their own mortality, which makes a lot of people uncomfortable. Fear of death is a great motivator, and when someone promises you immortality if you just believe hard enough (and send in a check every now and again), well, a lot of people take the bait. It's much easier, of course, if you were brought up in a religious family.
There are all sorts of mental tricks one can fall prey to, also. Confirmation bias, certainty bias, apophenia, pareidolia, etc. People tend to find what they're looking for, see what they want to see. Especially if they're undisciplined.