9 [In Migne, 8.] You see how, carried away by my love of the scriptures, I have exceeded the limits of a letter yet have not fully accomplished my object. We have heard only what it is that we ought to know and to desire, so that we too may be able to say with the psalmist:— “My soul breaks out for the very fervent desire that it has always unto your judgments.” But the saying of Socrates about himself— “this only I know that I know nothing” — is fulfilled in our case also.
The New Testament I will briefly deal with. Matthew, Mark, Luke and John are the Lord's team of four, the true cherubim or store of knowledge. With them the whole body is full of eyes, they glitter as sparks, they run and return like lightning, their feet are straight feet, and lifted up, their backs also are winged, ready to fly in all directions. They hold together each by each and are interwoven one with another: like wheels within wheels they roll along and go wherever the breath of the Holy Spirit wafts them. The apostle Paul writes to seven churches (for the eighth epistle— that to the Hebrews— is not generally counted in with the others).
He instructs Timothy and Titus; he intercedes with Philemon for his runaway slave. Of him I think it better to say nothing than to write inadequately. The Acts of the Apostles seem to relate a mere unvarnished narrative descriptive of the infancy of the newly born church; but when once we realize that their author is Luke the physician whose praise is in the gospel, we shall see that all his words are medicine for the sick soul. The apostles James, Peter, John, and Jude, have published seven epistles at once spiritual and to the point, short and long, short that is in words but lengthy in substance so that there are few indeed who do not find themselves in the dark when they read them.
The apocalypse of John has as many mysteries as words. In saying this I have said less than the book deserves. All praise of it is inadequate; manifold meanings lie hidden in its every word.
Source: Letters (New Advent)