"No man hath seen God at any time; the Only-begotten Son, which is in the bosom of the Father, He hath declared Him."
[1.] God will not have us listen to the words and sentences contained in the Scriptures carelessly, but with much attention. This is why the blessed David hath prefixed in many places to his Psalms the title "for understanding,"  and hath said, "Open Thou mine eyes, that I may behold wondrous things out of Thy Law." ( Ps. xxxii.42, &c.; Ps. cxix.18.) And after him his son again shows that we ought to "seek out wisdom as silver,  and to make merchandise of her rather than of gold." ( Prov. ii.4 and iii.14 [partially quoted]; John v.39.) And the Lord when He exhorts the Jews to "search the Scriptures," the more urges us to the enquiry, for He would not thus have spoken if it were possible to comprehend them immediately at the first reading. No one would ever search for what is obvious and at hand, but for that which is wrapt in shadow, and which must be found after much enquiry; and so to arouse us to the search He calls them "hidden treasure." ( Prov. ii.4; Matt. xiii.44.) These words are said to us that we may not apply ourselves to the words of the Scriptures carelessly or in a chance way, but with great exactness. For if any one listen to what is said in them without enquiring into the meaning, and receive all so as it is spoken, according to the letter, he will suppose many unseemly things of God, will admit of Him that He is a man, that He is made of brass, is wrathful, is furious, and many opinions yet worse than these. But if he fully learn the sense that lies beneath, he will be freed from all this unseemliness. ( Rev. i.15.) The very text which now lies before us says, that God has a bosom, a thing proper to bodily substances, yet no one is so insane as to imagine, that He who is without body is a body. In order then that we may properly interpret the entire passage according to its spiritual meaning, let us search it through from its beginning.
"No man hath seen God at any time." By what connection of thought does the Apostle come to say this? After showing the exceeding greatness of the gifts of Christ, and the infinite difference between them and those ministered by Moses, he would add the reasonable cause of the difference. Moses, as being a servant, was minister of lower things, but Christ being Lord and King, and the King's Son, brought to us things far greater, being ever with the Father, and beholding Him continually; wherefore He saith, "No man hath seen God at any time." What then shall we answer to the most mighty of voice, Esaias, when he says, "I saw the Lord sitting upon a throne high and lifted up" ( Isa. vi.1 ); and to John himself testifying of Him, that "he said these things when he had seen His glory"? ( c. xii.41.) What also to Ezekiel? for he too beheld Him sitting above the Cherubim. ( Ezek. i. and x.) What to Daniel? for he too saith, "The Ancient of days did sit" ( Dan. vii.9.) What to Moses himself, saying, "Show me Thy Glory, that I may see Thee so as to know Thee." ( Ex. xxxiii.13 , partly from LXX.) And Jacob took his name from this very thing, being called  "Israel"; for Israel is "one that sees God."  And others have seen him. How then saith John, "No man hath seen God at any time"? It is to declare, that all these were instances of (His) condescension, not the vision of the Essence itself unveiled. For had they seen the very Nature, they would not have beheld It under different forms, since that is simple, without form, or parts, or bounding lines. It sits not, nor stands, nor walks: these things belong all to bodies. But how He Is, He only knoweth. And this He hath declared by a certain prophet, saying, "I have multiplied visions, and used similitudes  by the hands of the prophets" ( Hos. xii.10 ), that is, "I have condescended, I have not appeared as I really was." For since His Son was about to appear in very flesh, He prepared them from old time to behold the substance of God, as far as it was possible for them to see It; but what God really is, not only have not the prophets seen, but not even angels nor archangels. If you ask them, you shall not hear them answering anything concerning His Essence, but sending up,  "Glory to God in the Highest, on earth peace, good will towards men." ( Luke ii.14.) If you desire to learn something from Cherubim or Seraphim, you shall hear the mystic song of His Holiness, and that "heaven and earth are full of His glory." ( Isa. vi.3.) If you enquire of the higher powers, you shall but find  that their one work is the praise of God. "Praise ye Him," saith David, "all His hosts." ( Ps. cxlviii.2.) But the Son only Beholds Him, and the Holy Ghost. How can any created nature even see the Uncreated? If we are absolutely unable clearly to discern any incorporeal power whatsoever, even though created, as has been often proved in the case of angels, much less can we discern the Essence which is incorporeal and uncreated. Wherefore Paul saith, "Whom no man hath seen, nor can see." ( 1 Tim. vi.16.) Does then this special attribute  belong to the Father only, not to the Son? Away with the thought. It belongs also to the Son; and to show that it does so, hear Paul declaring this point, and saying, that He "is the Image of the invisible God." ( Col. i.15.) Now if He be the Image of the Invisible, He must be invisible Himself, for otherwise He would not be an "image." And wonder not that Paul saith in another place, "God was manifested in the Flesh" ( 1 Tim. iii.16 ); because the manifestation  took place by means of the flesh, not according to (His) Essence. Besides, Paul shows that He is invisible, not only to men, but also to the powers above, for after saying, "was manifested in the Flesh," he adds, "was seen of angels."
[2.] So that even to angels He then became visible, when He put on the Flesh; but before that time they did not so behold Him, because even to them His Essence was invisible.
"How then," asks some one, "did Christ say, Despise not one of these little ones, for I tell you, that their angels do always behold the face of My Father which is in heaven'? ( Matt. xviii.10.) Hath then God a face, and is He bounded by the heavens?" Who so mad as to assert this? What then is the meaning of the words? As when He saith, "Blessed are the pure in heart, for they shall see God" ( Matt. v.8 ), He means that intellectual vision which is possible to us, and the having God in the thoughts; so in the case of angels, we must understand  that by reason of their pure and sleepless  nature they do nothing else, but always image to themselves God. And therefore Christ saith, that "No man knoweth the Father, save the Son." ( Matt. x.27.) What then, are we all in ignorance? God forbid; but none knoweth Him as the Son knoweth Him. As then many  have seen Him in the mode of vision permitted to them, but no one has beheld His Essence, so many of us know God, but what His substance can be none knoweth, save only He that was begotten of Him. For by "knowledge" He here means an exact idea and comprehension, such as the Father hath of the Son. "As the Father knoweth Me, even so know I the Father." ( c. x.15.)
Observe, therefore, with what fullness  the Evangelist speaks; for having said that "no man hath seen God at any time," he does not go on to say, "that the Son who hath seen, hath declared Him," but adds something beyond "seeing" by the words, "Who is in the bosom of the Father"; because, "to dwell  in the bosom" is far more than "to see." For he that merely "seeth" hath not an in every way exact knowledge of the object, but he that "dwelleth in the bosom" can be ignorant of nothing. Now lest when thou hearest that "none knoweth the Father, save the Son," thou shouldest assert that although He knoweth the Father more than all, yet He knoweth not how great He is, the Evangelist says that He dwells in the bosom of the Father; and Christ Himself declares, that He knoweth Him as much as the Father knoweth the Son. Ask therefore the gainsayer, "Tell me, doth the Father know the Son?" And if he be not mad, he will certainly answer "Yes." Then ask again; "Doth He see and know Him with exact vision and knowledge? Doth He know clearly what He Is?" He will certainly confess this also. From this next collect the exact comprehension the Son has of the Father. For He saith, "As the Father knoweth me, even so know I the Father" ( c. x.15 ); and in another place, "Not that any man hath seen the Father, save He which is of God." ( c. vi.46.) Wherefore, as I said, the Evangelist mentions "the bosom," to show all this to us by that one word; that great is the affinity and nearness of the Essence, that the knowledge is nowise different, that the power is equal. For the Father would not have in His bosom one of another essence, nor would He have dared, had He been one amongst many servants, to live  in the bosom of his Lord, for this belongs only to a true Son, to one who has  much confidence towards His Father, and who is in nothing inferior to Him.
Wouldest thou learn also His eternity? Hear what Moses saith concerning the Father. When he asked what he was commanded to answer should the Jews enquire of him, "Who it was that had sent him," he heard these words: "Say, I AM hath sent me." ( Ex. iii.14.) Now the expression "I AM,"  is significative of Being ever, and Being without beginning, of Being really and absolutely. And this also the expression, "Was in the beginning," declares, being indicative of Being ever; so that John uses this word to show that the Son Is from everlasting to everlasting  in the bosom of the Father. For that you may not from the sameness of name, suppose that He is some one of those who are made sons by grace, first, the article is added, distinguishing Him from those by grace. But if this does not content you, if you still look earthwards, hear a name more absolute than this, "Only-Begotten." If even after this you still look below, "I will not refuse," says he, (St. John,) "to apply to God a term belonging to man, I mean the word bosom,' only suspect nothing degrading." Dost thou see the lovingkindness and carefulness of the Lord? God applies  to Himself unworthy expressions, that even so thou mayest see through them, and have some great and lofty thought of Him; and dost thou tarry below? For tell me, wherefore is that gross and carnal word "bosom" employed in this place? Is it that we may suppose God to be a body? Away, he by no means saith so. Why then is it spoken? for if by it neither the genuineness of the Son is established, nor that God is not a body, the word, because it serves no purpose, is superfluously thrown in. Why then is it spoken? For I shall not desist from asking thee this question. Is it not very plain, that it is for no other reason but that by it we might understand the genuineness of the Only-Begotten, and His Co-eternity with the Father?
[3.] "He hath declared Him," saith John. What hath he declared? That "no man hath seen God at any time"? That "God is one"? But this all the other prophets testify, and Moses continually  exclaims, "The Lord thy God is one Lord" ( Deut. vi.4 ); and Esaias, "Before Me there was no God formed, neither shall there be after me." ( Isa. xliii.10.) What more then have we learned from "the Son which is in the bosom of the Father"? What from "the Only-Begotten"? In the first place, these very words were uttered by His working; in the next place, we have received a teaching that is far clearer, and learned that "God is a spirit, and they that worship Him must worship Him in spirit and in truth" ( c. iv.24 ); and again, that it is impossible to see God; "that no man knoweth" Him, "save the Son" ( Matt. xi.27 ); that He is the Father of the true and Only-Begotten; and all other things that are told us of Him. But the word "hath declared"  shows the plainer and clearer teaching which He gave not to the Jews only but to all the world, and established. To the prophets not even all the Jews gave heed, but to the Only-Begotten Son of God all the world yielded and obeyed. So the "declaration" in this place shows the greater clearness of His teaching, and therefore also He is called "Word," and "Angel  of great Counsel." 
Since then we have been vouchsafed a larger and more perfect teaching, God having no longer spoken by the prophets, but "having in these last days spoken to us by His Son" ( Heb. i.1 ), let us show forth a conversation far higher than theirs, and suitable to the honor bestowed on us. Strange would it be that He should have so far lowered Himself, as to choose to speak to us no longer by His servants, but by His own mouth, and yet we should show forth nothing more than those of old. They had Moses for their teacher, we, Moses' Lord. Let us then exhibit a heavenly wisdom  worthy of this honor, and let us have nothing to do with earth. It was for this that He brought His teaching from heaven above, that He might remove our thoughts thither, that we might be imitators of our Teacher according to our power. But how may we become imitators of Christ? By acting in everything for the common good, and not merely seeking our own. "For even Christ," saith Paul, "pleased not Himself, but as it is written, The reproaches of them that reproached Thee fell on Me." ( Rom. xv.3; Ps. lxix.9.) Let no one therefore seek his own. In truth, a man (really) seeks his own good when he looks to that of his neighbor. What is their good is ours; we are one body, and parts and limbs one of another. Let us not then be as though we were rent asunder. Let no one say, "such a person is no friend of mine, nor relation, nor neighbor, I have nought to do with him, how shall I approach, how address him?" Though he be neither relation nor friend, yet he is a man, who shares the same nature with thee, owns the same Lord, is thy fellow-servant, and fellow-sojourner,  for he is born in the same world. And if besides he partakes of the same faith, behold he hath also become a member of thee: for what friendship could work such union, as the relationship of faith? And our intimacy one with another must not be such nearness only as friends ought to show to friends, but such as is between limb and limb, because no man can possibly discover any intimacy greater than this sort of friendship and fellowship.  As then you cannot say, "Whence arises my intimacy and connection with this limb?" (that would be ridiculous;) so neither can you say so in the case of your brother. "We are all baptized into one body" ( 1 Cor. xii.13 ), saith Paul. "Wherefore into one body?" That we be not rent asunder, but preserve the just proportions of that one body by our intercourse and friendship one with another.
Let us not then despise one another, lest we be neglectful of ourselves.  "For no man ever yet hated his own flesh, but nourisheth and cherisheth it." ( Eph. v.29.) And therefore God hath given to us but one habitation, this earth, hath distributed all things equally, hath lighted one sun for us all, hath spread above us one roof, the sky, made one table, the earth, bear  food for us. And another table hath He given far better than this, yet that too is one, (those who share our mysteries understand my words,) one manner of birth He hath bestowed on all, the spiritual, we all have one country, that in the heavens, of the same cup drink we all. He hath not bestowed on the rich man a gift more abundant and more honorable, and on the poor one more mean and small, but He hath called all alike. He hath given carnal things with equal regard to all,  and spiritual in like manner. Whence then proceeds the great inequality of conditions in life? From the avarice and pride of the wealthy. But let not, brethren, let not this any longer be; and when matters of universal interest and more pressing necessity bring us together, let us not be divided by things earthly and insignificant: I mean, by wealth and poverty, by bodily relationship, by enmity and friendship; for all these things are a shadow, nay less substantial than a shadow, to those who possess the bond of charity from above. Let us then preserve this unbroken, and none of those evil spirits  will be able to enter in, who cause division in so perfect union;  to which may we all attain by the grace and lovingkindness of our Lord Jesus Christ, by whom and with whom, to the Father and the Holy Ghost, be glory, now and ever, and world without end. Amen.
 eis sunesin mskyl Maschil, sunesis, intellectus, et ut Hieron. reddit, eruditio, aliqui, erudiens, vel intellectum præstans. Lorin. in tit. Ps. 31 (32).  Some mss. read "silver, and search for it as treasure; He would not have said Search, &c."  gnostos.  Augus. De Civ. Dei, lib. 16, 39.  lit. "been likened."  al. "only singing."  al. "they shall answer again."  e xaireton.  al. therefore saith (Paul), "Who was manifested in the flesh," for the manifestation, &c.  al. "many say."  a grupnon.  al. "many prophets."  periousias, al. "exactness."  e ndiaitasthai.  trephesthai, al. strephesthai, versari.  lit. "uses."  lit. "He Who Is." Another reading of the passage is, "if he were asked...and should answer, he is bidden to say that, &c."  a narchos kai aidios.  al. "allows to be applied."  a no kai kato.  e xegesato.  or, "Messenger."  megales boules angelos. The LXX. version of the titles of Christ, Isaiah 9:6.  philosophian.  ho moskenos, "tent-fellow."  al. "care."  al. "let us then so care for our neighbors, as not neglecting each his own flesh."  a neken.  ho motimos.  al. "passions."  al. "union with Him."
 Some mss. read "silver, and search for it as treasure; He would not have said Search, &c."
 Augus. De Civ. Dei, lib. 16, 39.
 lit. "been likened."
 al. "only singing."
 al. "they shall answer again."
 e xaireton.
 al. therefore saith (Paul), "Who was manifested in the flesh," for the manifestation, &c.
 al. "many say."
 a grupnon.
 al. "many prophets."
 periousias, al. "exactness."
 e ndiaitasthai.
 trephesthai, al. strephesthai, versari.
 lit. "uses."
 lit. "He Who Is." Another reading of the passage is, "if he were asked...and should answer, he is bidden to say that, &c."
 a narchos kai aidios.
 al. "allows to be applied."
 a no kai kato.
 e xegesato.
 or, "Messenger."
 megales boules angelos. The LXX. version of the titles of Christ, Isaiah 9:6.
 ho moskenos, "tent-fellow."
 al. "care."
 al. "let us then so care for our neighbors, as not neglecting each his own flesh."
 a neken.
 ho motimos.
 al. "passions."
 al. "union with Him."