1. Because God has endowed us with a creative imagination, it is possible to fantasize about sceptical scenarios which we cannot escape, viz. Descartes' evil genie, a brain in a vat, a butterfly dreaming he's a man, and so on and so forth.
But there's a difference between artificial, make-believe scepticism and genuine doubt. The merely abstract possibility that I might be in error is not a rational basis for doubt. I need a specific reason to doubt a specific belief.
For example, it's possible that I'm insane. After all, one characteristic of crazy people is the belief that they are sane and everyone else is insane.
But is that a good reason to doubt my sanity?
2. There are two different ways of doing epistemology. You can start with all of the objections to knowledge and certainty, and then try to climb out of the hole you've dug for yourself.
Or you can start with the fact that we are able to successfully execute certain noetic tasks, and then ask the preconditions which make that possible.
3. For example, take the act of communication. It is possible for people to misunderstand each other. What is more, people often do misunderstand each other.
Now, you could start with the problem of miscommunication. And you could emphasize how that erodes certainty. But if you go down that narrow, twisting road you will probably lose your way, be unable to back out or turn around.
Instead of starting with the problem of miscommunication, it is better to start with examples of successful communication. How is that possible?
After all, even the skeptic presupposes the possibility of successful communication. His scepticism depends on it. Otherwise, he could not successfully communicate his scepticism!
4. The noetic effects of sin are not the same for the regenerate and unregenerate alike. God has certain intentions for the elect that he doesn't have for the reprobate. God intends to bring the elect to a saving knowledge of the truth by means of a verbal revelation.
5. It is true that we use our senses to acquire a knowledge of Scripture. But the stock objections to sense knowledge aren't very relevant to that particular activity.
You know the stock objections: the problem of induction, viz. how many samples constitute a representative sample? Why assume that the future will resemble the past?
The veil of perception. Is grass really green? Where is the color? In the sensible? In the mind?
Spatiotemporal paradoxes of infinite divisibility. That sort of thing.
But none of these familiar conundra is terribly relevant to processing propositional information from an audiovisual medium.
It doesn't matter what color the Bible really is. Reading or hearing the Bible is not like counting black ravens.
Sure, it's possible to misread or mishear the message. But that brings us back to point #4. We're only able to correct our error, to know that we misread or misheard the message if it's possible to successfully process propositional information. That sets the benchmark. Even the skeptic can't make his case unless he can successfully convey his sceptical arguments.
Again, the skeptic could contend that the acquisition of language is an empirical process (although Chomsky would demur). And he could raise familiar difficulties about how we fix the referent.
But the fact remains that he himself is dependent on language, he himself is able to fix the referent; otherwise, his case for scepticism would be abortive.
So even the skeptic must tacitly begin with successful communication as the framework within which to discuss miscommunication.
And that invites a transcendental argument: what are the necessary and sufficient truth-conditions which make this possible? Or as James Anderson would put it: "If knowledge, then God."