Once you study Psychology and Philosophy and come to realize the impossibility of choosing what to believe, you immediately have to rethink all the terms of at least American Evangelicalism.
That’s because God is an idea that either dawns on you as being the case, or not. There is no choosing. We cannot believe something is false while thinking it true, or vice versa. Something must seem to genuinely be the case before we will believe that it is.
So, Paul and John cannot mean that our epistemic beliefs about religious propositions are what matter to God or salvation. The Calvinist may be able to assert that, yes, we have nothing to do with anything; it is all God. But then that destroys the call to evangelize, castrates the claim that you must choose to believe (or even that it matters whether or not what is believed is “correct”), or die in Hell, but at least he’d be consistent.
In any case, if salvation doesn’t hang at all on epistemic belief, then the question is there, begging to be answered by study.