Duck Schuler, writing in Credenda/Agenda magazine, Volume 14, Issue 3: Musica - Lectionary and the Church Calendar, uses the metaphor of a lens:
"They act as lenses to bring our myopic and astigmatic vision into clearer focus. We are myopic and astigmatic because of our fallen nature. We need tools such as the Scripture and scriptural principles to act as our lenses. It is nearly impossible to not use some lens. We may either choose those that work or those that don't. But we look through them in order to see what we must see. The lens is not the substance of our study, Christ is.
"So we must choose our lenses carefully and with wisdom. Then we must use them properly." (em)
This confirms and clarifies the idea that the scriptures themselves are given to us, not as an end in themselves to be focused on in themselves, but as clues, in the LTK sense, to point us to God. We are never to place our trust in the means of grace, but only in the person and work of Christ whose grace flows to us through them. Only belief in the promises of God, fulfilled by Christ, will be accounted to us for righteousness. But the English syntax can be deceptive there. We stand not on the promises themselves, as bare statements, but on the Promiser Himself, our Rock, our Redeemer. We must rely in the LTK sense on the clues we are given, since they were given to us, and since they are all that we can directly perceive. But we do so not because there is something magical in the clues themselves. Ultimately, true faith relies on a person, on The Person, in whose image we are made. Ultimately, all roads lead to Rome. All clues point to Christ.