My brother's comment about Stela 5 reminded me of the books and CDs my parents sent to me to try to help me regain my testimony. After reading and listening to them I wondered if they'd even bothered to read or listen to them. In several cases they confirmed facts that my father had stated that he couldn't possibly believe were true that were obvious attacks by the enemies of the church. But mostly, they didn't tell me anything I didn't already know and were a confirmation of things that I'd only learned when I started reading non-Mormon sources. I also discovered that they conveniently failed to mention facts or information that weren't helpful to their argument. And finally I found that they made some of the most egregious logical flaws in leaping to conclusions that either weren't supported or were explicitly contradicted by their own facts.
Unfortunately, they don't feel they need to study or understand because the Spirit has already told them what the truth is and nothing is stronger for them than that witness and the good feelings it gives them.