Many, if not most, church affiliated people are convinced that God demands right doctrine and practice in order to be acceptable. If one operates under this assumption, then any opposing doctrines or beliefs are threatening, because they might convince some hearer and cause them to suffer horrendous eternal consequences. A religious system which requires right knowledge on penalty of hellfire cannot take chances.
It is a real conundrum for one who thinks they currently have right knowledge. If they want to actually verify the correctness of their current beliefs by studying the Bible and pondering the questions it raises, they have to consider the possibility that such study could just as easily lead them into error as it could validate or reveal the truth. Genuine study, honest questioning, a life long search for true and deeper meaning, all of things are a mixed bag. It might be good; but, if it turns out badly, it's going to be real bad.
In this mindset it is so much easier and seemingly safer to just accept what you have been taught, tamp down any questions, and remain silent, making no effort to grow in knowledge or try to resolve lingering doubts. The preacher may moan about the lack of Bible reading and knowledge that results from this spiritual lethargy. At the same time, it is fairly certain that he does not relish a group which insists on answers to the really tough questions potentially raised by serious Bible students. Superficial reading is fine. A working knowledge of Bible events, chronology. and history are impressive. Serious delving into authorship, dating, canonization, translations, linguistics, symbolism, translations, etc.- that's getting carried away and just likely to cause problems in the church. Students can be a little annoying when they begin to think they are nearly as bright as the instructor.
The good Christian therefore reads his Bible but lets the preacher tell him what it means. Your job is to merely look at the words. The God called minister is the one who is empowered to discern right from wrong, and therefore, dangerous doctrine. Trying to do too much in your Bible study is a prideful thing. Don't step out of the laymen's role without proper approval.