1 In the four Gospels, or rather in the four books of the one Gospel, Saint John the apostle, not undeservedly in respect of his spiritual understanding compared to the eagle, has elevated his preaching higher and far more sublimely than the other three; and in this elevating of it he would have our hearts likewise lifted up. For the other three evangelists walked with the Lord on earth as with a man; concerning His divinity they have said but little; but this evangelist, as if he disdained to walk on earth, just as in the very opening of his discourse he thundered on us, soared not only above the earth and above the whole compass of air and sky, but even above the whole army of angels and the whole order of invisible powers, and reached to Him by whom all things were made; saying, “In the beginning was the Word, and the Word was with God, and the Word was God.
This was in the beginning with God. All things were made by Him, and without Him was nothing made.” To this so great sublimity of his beginning all the rest of his preaching well agrees; and he has spoken concerning the divinity of the Lord as none other has spoken. What he had drank in, the same he gave forth. For it is not without reason that it is recorded of him in this very Gospel, that at supper he reclined on the Lord's bosom. From that breast then he drank in secret; but what he drank in secret he gave forth openly, that there may come to all nations not only the incarnation of the Son of God, and His passion and resurrection, but also what He was before His incarnation, the only Son of the Father, the Word of the Father, coeternal with Him that begot, equal with Him by whom He was sent; but yet in that very sending made less, that the Father might be greater.
Source: Tractates on the Gospel of John (New Advent)