Alternate First Principles

After explaining my epistemological beliefs (see, for example, this post), for some reason, the following question I most often receive goes something like this:

"The Qur’an claims to be God-breathed. Why do you not consider those writings to be Scripture?"

My answer is twofold:

A. Historically, I believe the Protestant canon to be God's word because God regenerated me, and as a regenerate I hear and submit to the voice of my Shepherd

B. Propositionally:

1. The Qur’an is not referenced in Scripture, so I could not account for its existence – let alone its inspiration, sufficiency, consistency, &c. – within my world-view. Which brings me to point two:

2. Not only is the burden of proof on the one who asserts that the Qur’an is inspired et. al. to demonstrate its internal consistency (particularly, that it even claims to be these things), but the Qur’an also must have answers to relevant epistemological questions, such as how one comes to know the Qur’an in the first place. 

These epistemic tests, I have found, fully refute Islamists (or whoever) who try to "copy-cat" Scripturalism. Obviously, I won’t generalize this, as the primary point I try to make is that every epistemology stands or falls on the merits of its first principle[s] and that an argument against a first principle should be a reductio ad absurdem. My first principle is such that world-views other than Christianity are virtually de facto falsified (I say virtually because there is obviously some trivial derivation from my first principle to the conclusion). The objector’s proposed first principle – in this instance, “the Qur’an is God-breathed et. al.” – fails to answer the relevant epistemological questions. That this is repeatedly the case is not surprising.

Ephesians 5:6-7 Let no one deceive you with empty words, for because of such things God's wrath comes on those who are disobedient. Therefore do not be partners with them.