If a requirement to believe is essential to salvation then any doubts about what to believe become potentially damning. I can't claim to believe and doubt at the same time. Since having questions and expressing them is an admission of uncertainty about what to believe, then any attempt to clarify and solidify my personal beliefs is a spiritual indictment. This is the spiritual state into which the traditional church entraps its members.
By teaching and demanding that believing properly is the way to please God and avoid His wrath, the church effectively constrains any impulse to question church doctrine which supposedly defines proper belief. Even those members who have real questions will not likely voice them because to do so identifies them as a non-believer and therefore subject to criticism and ostracism. The vast majority of members thus become conditioned to accepting church doctrine without any real evaluation. The unquestioning silence which is everywhere evident in the church is no real indication that members are perfectly satisfied with what is being taught. Many just go along to get along.
If salvation actually depends on rght knowledge and right belief as taught, then the conundrum described above is unavoidable. So what does that tell us? Well, either God enjoys toying with us with our eternal destiny at stake, or maybe we don't understand how salvation actually works. You are free to choose which is most likely, but I believe the latter.