In my often mentioned 58 years in the cult, I only met one person who I was sure believed it all 100%, well almost.
It is my sister, she is still in, and will support the cult till she dies, except , even in her case, there is one thing, she told me the other day that she will never "do Shunning".
That's good, as I run the risk of being DF'd all the time. LOL
Every other person that I spoke to in those years expressed at least some small doubt, or disagreement.