1. Certainty about information being true is properly justified according to the source of that information.
2. God is the ultimate and only infallible source of information.
3. Therefore, certainty in the strictest sense is only possible via revelation from God.
4. Perspicuity is important to certainty.
5. Scripture is the highest form of revelation, because it is the most perspicuous.
6. Scripture is not God's only revelation to men, for Scripture itself testifies clearly to general revelation.
7. General revelation may not teach much clearly, but it does clearly teach the existence of God, time, space, general morality, and logic (inter alia).
8. General revelation is manifest in one way by the imprint on the human heart of the knowledge of the existence of God, [one's own existence - the existence of other minds], time, space, general morality, and logic (inter alia).
8. If Scripture teaches a proposition, that proposition is necessarily true.
9. No other teacher besides Scripture (at the present time) both provides propositions and shares this quality of infallibity.
10. Therefore, nothing can be known with absolute certainty aside from what is taught in Scripture [or General Revelation] or what is properly deduced from Scripture [and/or General Revelation].
11. Men, however, are capable of using imperfect knowledge.
12. Some knowledge is more imperfect than other knowledge.
Hopefully this list of 12 items spells out a framework of epistemology that is understandable, even if not everyone agrees.