In a letter (HERE) based upon Ecclesiastes 12:12, John Newton makes the case that wide reading does not necessarily relate to true intelligence:

An eager desire of reading many books, though it is often supposed to be the effect of a taste for knowledge, is perhaps a principal cause of detaining multitudes in ignorance and perplexity. When an inexperienced person thus ventures into the uncertain tide of opinions, he is liable to be hurried hither and thither with the changing stream; to fall in with every new proposal, and to be continually perplexed with the difficulty of distinguishing between probability and truth. Or if, at last, he happily finds a clue to lead him through the labyrinth wherein so many have been lost, he will acknowledge, upon a review, that from what he remembers to have read (for perhaps the greater part he has wholly forgotten), he has gained little more than a discovery of what mistakes, uncertainty, insignificance, acrimony, and presumption, are often obtruded on the world under the disguise of a plausible title-page.

He is making the point that absorbing vast amounts of information can lead to vast confusion and even, in a sense, vast ignorance. ‘Learning’ or the appearance of intelligence can give an illusion of wisdom as much as a nice title can give the illusion of good content.

He then urges the necessity of reading Scripture.

But should we only read Scripture? His answer is ‘no’:

Allowing, therefore, the advantage of a discreet and seasonable use of human writings, I would point out a still more excellent way for the acquisition of true knowledge: a method which, if wholly neglected, the utmost diligence in the use of every other means will prove ineffectual; but which, if faithfully pursued, in an humble dependence upon the Divine blessing, will not only of itself lead us by the straightest path to wisdom, but will also give a double efficacy to every subordinate assistance.

Notice the takeaway here. If you read all the books in the world, but do not understand God’s Word, you will gain essentially nothing. But if you have God’s word, everything else you read will gain ‘a double efficiency’ in helping to understand the truth.

The Preacher of Ecclesiastes makes this point: “My son, beware of anything beyond these. Of making many books there is no end, and much study is a weariness of the flesh” (Ecc. 12:12). Wearing yourself out with reading and study serves no ultimate purpose in itself. But if that studying is mingled with the words of the “Shepherd,” it will lead to wisdom, stimulation (“goads”), and longevity (“nails”) (12:11).

Ecclesiastes 12:11 The words of the wise are like goads, and like nails firmly fixed are the collected sayings; they are given by one Shepherd.

At the end of his life, the Apostle Paul makes a request his younger student Timothy: “When you come, bring the cloak that I left with Carpus at Troas, also the books, and above all the parchments” (2 Tim. 4:13). He wants to read until the day that he dies. But above all he wants to read the Scriptures.

Do you want to be a doubly efficient reader? Do you want to enjoy books more? Do you want your experience with literature to be more deep and rich? Then read and digest the Scriptures and let them form your imagination as you come to other writings.