At times, people are not ready to accept/bear more. At times, if more had been revealed, it would not have been understood. At times, if more was to be revealed, it would be profanced. So, in the letter of the Word is revealed as much as is needed for the simple reformation, but not more. What is more is supposed to be further seen via the doctrinal points, provided they are genuinely derived and confirmed from the Word.
This idea has an easily accessible simile, your own parents. When you were small, no doubt your parents explained things to you in ways you could grasp, ways that an immature and inexperienced mind could grapple with a concept. Likewise, God does so for his newly born-from-above infantile followers. Those ideas which we call “mystery” necessarily include information too wonderful for human comprehension; concepts that will not conform to our dimensions of space and time, possibilities that to us are impossibilities. If a precise explanation of a miracle were to be explained to even the most intelligent human mind, I suspect that person’s head would explode. While we do not see a portion of the population walking about cerebrally truncated with bloody frayed necks, we know our loving Father is withholding that kind of decapitating detail.
There is also the fact that evil is no metaphor. That separates down two roads; the demise of believers, and the chance to avoid its own demise.
Evil is destroyed before judgement, it wants to know what is the exact reason for that to happen. It understands the logic for the beast and false prophet, but not the exact reason for it to be thrown in the lake in one sudden move. The answer is in scripture, but it does not know where it has been placed, and neither do we.
If scripture were to be seen as spoon feeding information, causing one universal belief system, it would only take evil one lie to bring it all down. That is pride saying otherwise. Humans are so addicted to what that thing spits out, we would believe the lie.