I was raised Mormon. Mormonism is somewhat unique in that it claims to have a modern prophet and leadership that are directly led by god, and it strongly encourages members to pray to god and ask god for confirmation that this is true. Mormons are also taught that god would not allow their prophet to lead them astray, and that your local leaders are also inspired by god in what they do in their official capacity.

I was a missionary when shit started to break. I had a nervous breakdown; I am on the autism spectrum (although that diagnosis wasn't available at that time; it was almost 30 years ago, back in DSM-III), and being a missionary was a lot too much for me for many, many reasons. I became suicidal. My leaders--again, people who were supposed to be called by god and led through inspiration from god--insisted that I must be acting in some sinful way, and that it was sin that had led to me being suicidal. They encouraged me to read my scriptures and pray more--as if I wasn't already doing that a lot as a missionary--and to repent of my sins (whatever they were, because I sure as fuck didn't know). If I was not sinning in some way, then Satan never could have taken hold in my heart, and Satan was obviously what was causing me to be suicidal. Obviously these commandments did not help, because I wasn't doing anything 'wrong' in the first place.

But that leads to a problem: I believed that these people were called by god, and acting under god's instructions, because I had received a spiritual witness. However, it was clear that they were wrong; I was not acting in a sinful manner (certainly less so than other missionaries!), and I had nothing to repent of. So these things are clearly contradictory: if I have received a spiritual confirmation from god that these men are led by him, then what they are saying must be from god and therefore true. But I know my own actions, and I know that I haven't done anything that is sinful under any remotely normal definition of sin. Therefore, the feelings that I believed were spiritual confirmation must not have been spiritual confirmation at all.

Once you realize that feelings can not be a reliable way of knowing if something is actually true or not (or True, for that matter), then all of it falls apart. You realize that 'answers' to prayers are just feelings, not communication from the divine. The bible is suddenly a book of myths. Miracles dissolve like fog in the sun. When you look at religion--not just Mormonism, but all religion, and you compare it against things that can be verified empirically, none of the claims stand up.

Even though the foundations of my faith cracked while I was a missionary, I was unable to accept the meaning for several years, because Mormonism is a cult, and it's very hard to escape even when you know it's garbage.