To someone raised in a cult, or with deeply held beliefs, there is very little difference between the two. In fact "fixing beliefs" is, in a sense, reality resculpting. We are our priors. A large part of our priors are the contents of our mind.

Honestly, I shudder at the isea we ever figure out how to "engineer" a belief into a person. As it stands, that is one technology we are not ready to have trivially available.