What rule hath God given to direct us how we may glorify and enjoy Him?

This is the second question of The Shorter Catechism. The answer to this question is:

The Word of God, which is contained in the Scriptures of the Old and New Testaments, is the only rule to direct us how we may glorify and enjoy Him.

The Scriptures are the sole authority when it comes to knowing how to glorify and enjoy God. While, this is seemingly obvious, interpreting the Scriptures rightly is by no means a foregone conclusion, especially in our post-modern world along with its (and various other) destructive hermenuetic. I don't say that to mean that the Bible can only be understood by the scholarly elite, for the overall message of the Bible can be determined and understood by all. But for those who seek to plumb the depth and enter the storehouses of treasure, right interpretation becomes something essential.

I do find it curious that although the Bible is explicitly stated in this second question, it is implicit in the first question. How else would we know what "the chief end of man" is without the Bible? The Bible as the "only rule" is presupposed before it is proposed. That would lead to an interesting discussion: how can something that is presupposed actually show up later as a proposition? Doesn't it cease to be presupposed? Maybe not, since the questions in the catechism unfold along a linear progression--one question leading to the next. Maybe it's simply self-revealing. You could go on forever if everything needed to be qualified, which leads to the very serious consideration of why did the writers of the catechism start with man's teleological end as revealed in Scripture, as opposed to starting with Scripture itself? Oh well, I digress.

Furthermore, the Scriptures were given to us by God, breathed by Him through the hand of men. We must come to the text as the text and let it speak for itself. We must come humbly and with faith, and we mustn't set ourselves over the text, but under, and let God's Holy Spirit show us the treasures that lie therein.

Lastly, the Scriptures are the Old and New Testaments, as if these are two separate and 'testaments.' They are indeed one, or maybe more accurately, the one was transformed into the other in a far more glorious manifestation. Whereas the one could only be articulated using shadow and dim reflection, the other provided the substance, namely Christ himself, who is the fulfillment of the Old Testament.