An apologetic preface about the Gospel of John the Apostle and Evangelist.

The disciple whom Jesus loved, who also reclined at his side at dinner, bears true witness in his gospel to the one who loved him, that he is the Christ, the Son of God, that he was not only born a human being at the end of the ages from the virgin's womb but also was begotten before all the ages God from God, his Father. Of course, all divinely-inspired scripture bears witness to this truth but both its occasion and also its structure clearly demonstrate that the special purpose of this work was to do so.

Its occasion demonstrates this because when John had been sent into exile by Domitian (who was the next persecutor of the Christians after Nero), heretics rushed against the church like wolves against sheepfolds bereft of their shepherd: Marcion, Cerinthus, and Ebion, and the rest of the antichrists who befouled the simplicity of the gospel faith with perverse teaching by denying that the Christ existed before Mary. And so, urged by nearly every bishop then in Asia, beseeching the Lord with the fasting prescribed for all, and filled with the grace of the Holy Spirit, he wrote this gospel in which he dispelled all the clouds of the heretics with the suddenly-appearing light of truth.

The structure of the work itself shows this because it conforms exactly to the requirements of legal witness. For he joins to himself another witness, no less suitable, that is, John the Baptist, so that there may be two witnesses since no statement will stand on the testimony of fewer than two witnesses. Therefore having joined to himself the John who 'came as a witness that he may bear witness to the light,' John the evangelist often calls his words as well as his own 'witness,' saying about himself at the end of all their sayings: 'This is the disciple who bears witness of these things and he has written this and we know that his witness is true.'

Therefore he is a singular and special witness of the Son of God. When disputes arose not simply about the boundaries and laws of the Kingdom but about the children of the King himself, wearied by other witnesses and worn down by the noise of vehement nay-sayers, he suddenly thrust himself into the midst of them, openly before the whole of creation. With a thunderous gospel voice and the lightening of flashing words, he terrified and put to flight the whole council of emptiness and every assembly of ill-wishers anywhere in the world by openly bearing witness to the Son, that he is the only and consubstantial Son and thereby the lawful heir of the eternal Father.

This act of witness wonderfully favours our hopes, that is, the hopes of all of us wards whom he has written in as co-heirs to the eternal testament by his blood, which hopes are endangered by the great disparagements of our adversaries. In what way? How will that testament by which he has bequeathed a heavenly inheritance to us be established, if he himself was not the lawful possessor of heaven? How was heaven his possession, if he himself did not come down from heaven but had his beginning from Mary? Therefore as I say this faithful witness came opportunely to bolster our hopes when he, proclaiming the ancient rights of the rightful testator, declared not only that heaven but everything which exists is the Son's, but even more: that everything was made by him and that without him nothing was made.

We therefore, who examine the scriptures which testify to the Son of God and delight in the way of its testimonies as in great wealth, we ought all especially to examine this testimony and scrutinise it with our whole heart, desiring it with all our mind and loving it above gold and precious stones. For if we are merchants like the one in the gospel and seek fine pearls, behold! here we find a precious pearl. Where can any of greater value be found? God the true lover of souls, lover of the beloved soul of John, fixed this pearl in his heart as a memorial of special affection so that his virgin state, belonging to him before all the saints, might proclaim with a lively voice to humankind that very Word which the Virgin Mary alone bore in the flesh. So those who study sacred letters in Christ's school must give away everything so as to buy that single pearl and cleanse their mind's eye from all the filth of physical affections. In that way, they are able to follow in some degree that eagle John whom a clean heart strengthened to be able to behold the brightness of the eternal Sun with unimpaired keenness of mind, beyond the other animals of Ezekiel's divine vision.

For the Lord spoke through Isaiah of the one who achieves true wisdom through the way of cleanness: 'He will dwell on the heights, the high places of the rocks will be his fortress, his bread will be supplied, his water assured. His eyes will see the king in his beauty, they will behold a land from afar' (Is 33.16-17, NRSV adpt). To make the point even clearer, the blessed Job said in different words but with the same meaning: 'At the Lord's command he will be lifted up like an eagle, he will place his nest in difficult places; he lives upon the rocks, and makes his home among broken flints and inaccessible stones. From there he spies food, his eyes see it from far away' (Job 39.27-8, NRSV adpt).

And indeed John, the exalted beholder of this Word and its everlasting beginning, wonderfully conforms to all these passages. For he is lifted up like an eagle, gazing with open eyes at the rays of divinity; and he has placed his nest, that is, the eternal fortress of this his gospel, in difficult places; he lives upon the rocks, that is, on the firm foundation of truth; and from thence he spies his food, which indeed he deserves to attain, the glory of this everlasting Word. But in one passage above is said, 'His eyes will behold a land from afar' and in the other, 'His eyes see from far away.' For this eagle, even lifted up, does not yet see God directly but in a mirror, dimly. 'For,' he says, 'we are children of God now but what we shall be has not yet been made plain' (1 Jn 3.2). Even though his eaglets drink blood, that is, his hearers are fed only by the gore of the crucified Lord (which they do understand) because they cannot perceive the hidden mysteries of divinity, we are still in no way to be blamed for striving somehow to watch the flight of such a great eagle. For eaglets are nourished in the nest so that someday they will fly after their mother for the same food.

Therefore let us strive to follow the high mysteries toward which the great teacher Augustine flew like a great eagle by the same path but not in every respect with the same steps. For he flies about the high peaks of the mountains, while we shall occupy ourselves about the deepest roots as well. He hastens to pick each of the highest fruits of a very lofty tree; we try also to reach the twigs of the gospel letter nearest the earth which he has left behind for little ones so that, since loftier men have been satisfied by his high explanation of the mysteries now the continuation, which addresses the letter, may also succour the little ones, those who are like us.