With scripture, and some prophets, it's very close to the infallibility question. Those who believe in infallibility, either of scripture or of prophet, HAVE TO believe in what they believe, or drop the infallibility stuff.
But I see scripture as not covering life either. Let's take whether or not to get a vaccine. Sure, some folks might find some sort of scripture that they think tells them not to get it, but within many religious groups, everyone would have free choice, which means free thinking. My point is that so much of life isn't covered by scripture, and what can people turn to other than their own common sense, or lack of common sense?