Scripture can be understood externally and/or internally. It can dwell on the shallows, or deeply.
Unbelievers can understand, to a certain degree, the external clarity of Scripture. The Pharisees in the Bible are a good example of this. They were experts in the Scriptures, but failed to know that the Scriptures were all about Jesus. That is why they refused to believe Jesus’ testimony about himself. Many value the Bible for it’s wisdom, principles, history, stories et cetera. But that is it. Their appreciation stops there. It has no effect on their lives because there is no internal clarity.
To the believer, there is more. There is an internal clarity they experience from Scripture as well as an external. The Spirit which dwells in every believer, brings about this inward understanding. It goes beyond the surface.
Martyn Luther believed this distinction to be true. His perspective is explained by Bernard Ramm:
To Luther there was an outer and an inner clarity of Scripture. By the usual laws or rules of language, a Christian could understand the Scripture as a written document. This is the external clarity of Scripture. Due to man’s sinfulness he needs an inward assist so that he might grasp the spiritual Word of God as the Word of God. The Word of God is a spiritual entity and can only be understood in faith with the help of the Holy Spirit. This is the internal clarity of Scripture.
Soren Kierkegaard, illustrated this point in this way:
Kierkegaard poses the question how a lover reads a love letter from his lover when they happen to speak two different languages. The first thing the lover must do with the letter is to translate it. He gets out his dictionary of the foreign language—perhaps even a grammar—and goes to work. He translates it word by word, line by line, paragraph by paragraph, until the entire translated letter is on the desk before him. But doing all that hard work of translating that letter into his language is not to read the letter as a love letter. Now that he has the complete translation he relaxes, leans back in his chair, and reads the translated letter as a love letter. So it is with Holy Scripture. We cannot avoid all the hard work of looking up Hebrew and Greek words, puzzling over constructions, consulting commentaries, and other such helps. But doing this careful academic job of translating and interpreting Scripture is not to read the Word of God as the Word of God. Unfortunately that is where the professor stops. But to read Scripture as the Word of God he must read it the second time. Now it is no longer an academic task but it is a case of letting God’s Word get through to man’s soul as God’s Word. It is in the second reading of the letter that the Holy Spirit, the Hermes from heaven, enters into the process of understanding Holy Scripture.
He illustrates his point a second way:
A little boy is to be spanked by his father. While the father goes for the rod, the boy stuffs the bottom of his pants with several table napkins. When the father returns and administers the whipping the boy feels no pain as the napkins absorb the whack of the rod. The little boy represents the biblical scholars. They pad their britches with their lexicons, commentaries, and concordances. As a result the Scripture never reaches them as the Word of God. Having nullified its power by shielding themselves with their academic paraphernalia, they thus never hear the Scriptures as the Word of God. If they would unpack their books from their britches (which are necessary rightfully used, as illustrated in the story of the love letter) then the Scriptures could get through to them as the Word of God. Allowing Holy Scripture to get through to us as the Word of God is the special work of the Holy Spirit.
These block quotes were clipped from Preaching: How to Preach Biblically, which is available to purchase HERE.