Yes, I think that's true. There may be a sort of transference of trust involved. They started believing because they trusted the person(s) who taught them, and perhaps also feel a sense of being trusted by the same person(s) in return. A betrayal of the beliefs is then seen as if it is a betrayal of the source of those beliefs.
The reasons that people believe in religion (and absurd conspiracy theories, and insane political ideologies) are many, and those reasons can be woven together in complicated ways. This is why getting free from such beliefs can be a long, difficult, and painful process, if one gets free from them at all. And it's why such beliefs can seem oddly impervious to reason in an otherwise reasonable person.
A few years ago, I was working on a project under my carport when I was approached by three people who were walking around the neighborhood inviting people to their church. They were friendly and seemed well meaning, even if misguided, so I engaged them in conversation and politely told them that I do not believe in any of that, and that I have already been down that path and have no interest in revisiting it. They tried several different arguments to convince me to return to the fold. But every argument they offered centered on some supposed benefit of believing, in and of itself. The promise of Heaven. The threat of hell. The comfort of believing in life after death. Finding a sense of meaning. Being part of a community of believers. Etc. They offered not a single argument, not even a faulty one like the creationist bunkum that gets posted here, in support of their beliefs actually being true. Even after pointing this out, they still failed to come up with any argument (again, not even a bad one) favoring the truth of their beliefs, but only more arguments for the benefits of believing. It was as if truth was completely absent as a factor in why they believe what they believe. As if the thought hadn't even occurred to them.
This is why arguments based on hard evidence and sound reasoning so often fail to convince. Truth is not among their reasons for believing. It just doesn't factor in to it.
I sometimes think that the only way for skeptics to be effective at changing minds on a large scale may be to resort to using bad reasoning (emotion-loaded anecdotal stories, associating ideas with positive feelings, positive self-image, etc.) to lead people to correct, or at least rationally defensible, conclusions. But then I think that this is probably a bad idea, because if you change only the conclusions, not the mode of thinking, then people remain vulnerable to having those good conclusions displaced by bad ones by continuing with the same faulty thinking. It would be a never ending battle.
Maybe the real winning trick is to use bad reasoning to persuade people not of specific conclusions, such as evolution or that vaccines don't cause autism, but of the idea that truth should be the first and foremost factor in determining one's beliefs, and that evidence and sound reasoning are the best tools for evaluating truth. It may be that even if one reaches that point for wrong reasons, once one gets there, he/she can then use proper reasoning to stay there, thus breaking the chain of credulity.
