1. What we have just heard and attentively received, as the holy Gospel was being read, I doubt not that all of us have also endeavored to understand, and that each of us according to his measure apprehended what he could of so great a matter as that which has been read; and while the bread of the word is laid out, no one can complain that he has tasted nothing. But again I doubt not that there is scarcely any who has understood the whole. Nevertheless, even should there be any who may sufficiently understand the words of our Lord Jesus Christ now read out of the Gospel, let him bear with our ministry, whilst, if possible, with His assistance, we may, by treating thereof, cause that either all or many may understand that which a few are joyful of having understood for themselves.
2. I think that what the Lord says, "I am the light of the world, "is clear to those that have eyes, by which they are made partakers of this light: but they who have not eyes except in the flesh alone, wonder at what is said by the Lord Jesus Christ, "I am the light of the world." And perhaps there may not be wanting some one too who says with himself: Whether perhaps the Lord Christ is that sun which by its rising and setting causes the day? For there have not been wanting heretics who thought this. The Manichæans have supposed that the Lord Christ is that sun which is visible to carnal eyes, exposed and public to be seen, not only by men, but by the beasts. But the right faith of the Catholic Church rejects such a fiction, and perceives it to be a devilish doctrine: not only by believing acknowledges it to be such, but in the case of whom it can, proves it even by reasoning. Let us therefore reject this kind of error, which the Holy Church has anathematized from the beginning. Let us not suppose that the Lord Jesus Christ is this sun which we see rising from the east, setting in the west; to whose course succeeds night, whose rays are obscured by a cloud, which removes from place to place by a set motion: the Lord Christ is not such a thing as this. The Lord Christ is not the sun that was made, but He by whom the sun was made. For "all things were made by Him, and without Him was nothing made."
3. There is therefore a Light which made this light of the sun: let us love this Light, let us long to understand it, let us thirst for the same; that, with itself for our guide, we may at length come to it, and that we may so live in it that we may never die. This is indeed that Light of which prophecy long ago going before thus sang in the psalm: "O Lord, Thou shalt save men and beasts; even as Thy mercy is multiplied, O God." These are the words of the holy psalm: mark ye what the ancient discourse of holy men of God did premise concerning such a light. "Men," saith it, "and beasts Thou shalt save, O Lord; even as Thy mercy is multiplied, O God." For since Thou art God, and hast manifold mercy, the same multiplicity of Thy mercy reaches not only to men whom Thou hast created in Thine own image, but even to the beasts which Thou hast made subservient to men. For He who gives salvation to man, the same gives salvation also to the beast. Do not blush to think this of the Lord thy God: nay, rather believe this and trust it, and see thou think not otherwise. He that saves thee, the same saves thy horse and thy sheep; to come to the very least, also thy hen: "Salvation is of the Lord,"  and God saves these. Thou art uneasy, thou questionest. I wonder why thou doubtest. Shall He disdain to save who deigned to create? Of the Lord is the saving of angels, of men, and of beasts: "Salvation is of the Lord." Just as no man is from himself, so no man is saved by himself. Therefore most truly and right well doth the psalm say, "O Lord, Thou shall save men and beasts." Why? "Even as thy mercy is multiplied, O God." For Thou art God, Thou hast created, Thou savest: Thou gavest being, Thou givest to be in health.
4. Since, therefore, as the mercy of God is multiplied, men and beasts are saved by Him, have not men something else which God as Creator bestows on them, which He bestows not on the beasts? Is there no distinction between the living creature made after the image of God, and the living creature made subject to the image of God? Clearly there is: beyond that salvation common to us with the dumb animals, there is what God bestows on us, but not on them. What is this? Follow on in the same psalm: "But the sons of men shall hope under the covert of Thy wings." Having now a salvation in common with their cattle, "the sons of men shall hope under the covert of Thy wings." They have one salvation in fact, another in hope. This salvation which is at present is common to men and cattle; but there is another which men hope for; and which they who hope for receive, they who despair of receive not. For it saith, "The sons of men shall hope under covert of Thy wings." And they that perseveringly hope are protected by Thee, lest they be cast down from their hope by the devil: "Under covert of Thy wings they shall hope." If they shall hope, what shall they hope for, but for what the cattle shall not have? "They shall be fully drunk with the fatness of Thy house; and from the torrent of Thy pleasure Thou shalt give them drink." What sort of wine is that with which it is laudable to be drunk? What sort of wine is that which disturbs not the mind, but directs it? What sort of wine is that which makes perpetually sane, and makes not insane by drinking? "They shall be fully drunk." How? "With the fatness of Thy house; and from the torrent of Thy pleasure Thou shalt give them drink." How so? "Because with Thee is the fountain of life." The very fountain of life walked on the earth, the same who said, "Whoso thirsts, let him come unto me." Behold the fountain! But we begin to speak about the light, and to handle the question laid down from the Gospel concerning the light. For we read how the Lord said, "I am the light of the world." Thence arose a question, lest any one, carnally understanding this, should fancy this light to mean the sun: we came thence to the psalm, which having considered, we found meanwhile that the Lord is the fountain of life. Drink and live. "With Thee," it saith, "is the fountain of life;" therefore, "under the shadow of Thy wings the sons of men hope," seeking to be full drunk with this fountain. But we were speaking of the Light. Follow on, then; for the prophet, having said, "With Thee is the fountain of life," went on to add, "In Thy light shall we see light," -- God of God, Light of Light. By this Light the sun's light was made; and the Light which made the sun, under which He also made us, was made under the sun for our sake. That Light which made the sun, was made, I say, under the sun for our sake. Do not despise the cloud of the flesh; with that cloud it is covered, not to be obscured, but to be moderated.
5. That unfailing Light, the Light of wisdom, speaking through the cloud of the flesh, says to men, "I am the light of the world; he that followeth me shall not walk in darkness, but shall have the light of life." How He has withdrawn thee from the eyes of the flesh, and recalled thee to the eyes of the heart! For it is not enough to say, "Whoso followeth me shall not walk in darkness, but shall have light;" He added too, "of life;" even as it was there said, "For with Thee is the fountain of life." See thus, my brethren, how the words of the Lord agree with the truth of that psalm: both there, the light is put with the fountain of life, and by the Lord it is said, "light of life." But for bodily use, light and fountain are different things: our mouths seek a fountain, our eyes light; when we thirst we seek a fountain, when we are in darkness we seek light; and if we chance to thirst in the night, we kindle a light to come to a fountain. Not so with God: light and fountain are the same thing: He who shines for thee that thou mayest see, the same flows for thee that thou mayest drink.
6. You see, then, my brethren, you see, if you see inwardly, what kind of light this is, of which the Lord says, "He that followeth me shall not walk in darkness." Follow the sun, and let us see if thou wilt not walk in darkness. Behold, by rising it comes forth to thee; it goes by its course towards the west. Perhaps thy journey is towards the east: unless thou goest in a contrary direction to that in which it travels, thou wilt certainly err by following it, and instead of east wilt get to the west. If thou follow it by land, thou wilt go wrong; if the mariner follow it by sea, he will go wrong. Finally, it seems to thee, suppose, that thou must follow the sun, and thou also travellest thyself towards the west, whither it also travels; let us see after it has set if thou wilt not walk in darkness. See how, although thou art not willing to desert it, yet it will desert thee, to finish the day by necessity of its service. But our Lord Jesus Christ, even when He was not manifest to all through the cloud of His flesh, was yet at the same time holding all things by the power of His wisdom. Thy God is whole everywhere: if thou fall not off from Him, He will never fall away from thee.
7. Accordingly, "He that followeth me," saith He, "shall not walk in darkness, but shall have the light of life." What He has promised, He put in a word of the future tense; for He says not has, but "shall have the light of life." Yet He does not say, He that shall follow me; but, he that does follow me. What it is our duty to do, He put in the present tense; but what He has promised to them that do it, He has indicated by a word of the future tense. "He that followeth, shall have." That followeth now, shall have hereafter: followeth now by faith, shall have hereafter by sight. For, "whilst we are in the body," saith the apostle, "we are absent from the Lord: for we walk by faith, not by sight."  When shall we walk by sight? When we shall have the light of life, when we shall have come to that vision, when this night shall have passed away. Of that day, indeed, which is to arise, it is said, "In the morning I will stand near thee, and contemplate thee."  What means "in the morning"? When the night of this world is over, when the terrors of temptations are over, when that lion which goeth about roaring in the night, seeking whom it may devour, is vanquished. "In the morning I will stand near thee, and contemplate." Now what do we think, brethren, to be our duty for the present time, but what is again said in the psalm, "Every night through will I wash my couch; I will moisten my bed with my tears"?  Every night through, saith he, I will weep; I will burn with desire for the light. The Lord sees my desire: for another psalm says to Him, "All my desire is before Thee; and my groaning is not hid from Thee."  Dost thou desire gold? Thou canst be seen; for, while seeking gold, thou wilt be manifest to men. Dost thou desire corn? Thou askest one that has it; whom also thou informest, while seeking to get at that which thou desirest. Dost thou desire God? Who sees, but God? From whom, then, dost thou seek God, as thou seekest bread, water, gold, silver, corn? From whom dost thou seek God, except from God? He is sought from Himself who has promised Himself. Let the soul extend her desire, and with more capacious bosom seek to comprehend that which "eye hath not seen, nor ear heard, nor hath entered into the heart of man."  Desire it we can, long for it we can, pant after it we can; but worthily conceive it, worthily unfold it in words, we cannot.
8. Wherefore, my brethren, since the Lord says briefly, "I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life;" in these words He has commanded one thing, promised another; let us do what He has commanded, that we may not with shameless face demand what He has promised; that He may not say to us in His judgment, Hast thou done what I commanded, that thou shouldest expect what I promised? What hast Thou commanded, then, O Lord our God? He says to thee, That thou shouldest follow me. Thou hast sought counsel of life? Of what life, but of that of which it is said, "With Thee is the fountain of life"? A certain man heard it said to him," Go, sell all that thou hast, and give to the poor, and thou shalt have treasure in heaven; and come, follow me." He followed not, but went away sorrowful; he sought the "good Master," went to Him as a teacher, and despised His teaching; he went away sorrowful, tied and bound by his lusts; he went away sorrowful, having a great load of avarice on his shoulders. He toiled and fretted; and yet he thought that He, who was willing to rid him of his load, was not to be followed but forsaken. But after the Lord has, by the gospel, cried aloud, "Come unto me, all ye that labor, and are heavy laden, and I will give you rest; take my yoke upon you, and learn of me, for I am meek and lowly in heart,"  how many, on hearing the gospel, have done what that rich man, on hearing from His own mouth, did not do? Therefore, let us do it now, let us follow the Lord; let us loose the fetters by which we are hindered from following Him. And who is sufficient to loose such bonds, unless He help, to whom it is said, "Thou hast burst asunder my bonds"?  Of whom another psalm says, "The Lord looseth them that are in bonds; the Lord raiseth up them that are crushed and oppressed." 
9. And what do they follow, who have been loosed and raised up, but the Light from which they hear, "I am the light of the world: he that followeth me shall not walk in darkness"? For the Lord gives light to the blind. Therefore we, brethren, having the eye-salve of faith, are now enlightened. For His spittle did before mingle with the earth, by which the eyes of him who was born blind were anointed. We, too, have been born blind of Adam, and have need of Him to enlighten us. He mixed spittle with clay: "The Word was made flesh, and dwelt among us." He mixed spittle with earth; hence it was predicted, "Truth has sprung from the earth;"  and He said Himself, "I am the way, the truth, and the life." When we shall see face to face, we shall have the full fruition of the truth; for this also is promised to us. For who would dare hope for what God had not deigned either to promise or to give? We shall see face to face. The apostle says, "Now I know in part, now through a glass darkly; but then, face to face."  And the Apostle John says in his epistle, "Beloved, now are we the sons of God; and it has not yet appeared what we shall be: we know that, when He shall appear, we shall be like Him; for we shall see Him even as He is."  This is a great promise; if thou lovest, follow. I do love, sayest thou, but by what way am I to follow? If the Lord thy God had said to thee, "I am the truth and the life," in desiring truth and longing for life, thou mightest truly ask the way by which thou mightest come to these, and mightest say to thyself: A great thing is the truth, a great thing is the life, were there only the means whereby my soul might come thereto! Dost thou ask by what way? Hear Him say at the first, "I am the way." Before He said whither, He premised by what way: "I am," saith He, "the way." The way whither? "And the truth and the life." First, He told thee the way to come; then, whither to come. I am the way, I am the truth, I am the life. Remaining with the Father, the truth and life; putting on flesh, He became the way. It is not said to thee, Labor in finding a way to come to the truth and life; this is not said to thee. Sluggard, arise: the way itself has come to thee, and roused thee from thy sleep; if, however, it has roused thee, up and walk. Perhaps thou art trying to walk, and art not able, because thy feet ache. How come thy feet to ache? Have they been running over rough places at the bidding of avarice? But the word of God has healed even the lame. Behold, thou sayest, I have my feet sound, but the way itself I see not. He has also enlightened the blind.
10. All this by faith, so long as we are absent from the Lord, dwelling in the body; but when we shall have traversed the way, and have reached the home itself, what shall be more joyful than we? What shall be more blessed than we? Because nothing more at peace than we; for there will be no rebelling against a man. But now, brethren, it is difficult for us to be without strife. We have indeed been called to concord, we are commanded to have peace among ourselves; to this we must give our endeavor, and strain with all our might, that we may come at last to the most perfect peace; but at present we are at strife, very often with those whose good we are seeking. There is one who goes astray, thou wishest to lead him to the way; he resists, thou strivest with him: the pagan resists thee, thou disputest against the errors of idols and devils; a heretic resists, thou disputest against other doctrines of devils; a bad catholic is not willing to live aright, thou rebukest even thy brother within; he dwells with thee in the house, and seeks the paths of ruin; thou art inflamed with eager passion to put him right, that thou mayest render to the Lord a good account of both concerning him. How many necessities of strife there are on every side! Very often one is overcome with weariness, and says to himself, "What have I to do with bearing with gainsayers, bearing with those who render evil for good? I wish to benefit them, they are willing to perish; I wear out my life in strife; I have no peace; besides, I make enemies of those whom I ought to have as friends, if they regarded the good will of him that seeks their good: what business is it of mine to endure this? Let me return to myself, I will be kept to myself, I will call upon my God. Do return to thyself, thou findest strife there. If thou hast begun to follow God, thou findest strife there. What strife, sayest thou, do I find? "The flesh lusteth against the Spirit, and the Spirit against the flesh."  Behold thou art thyself, thou art alone, thou art with thyself; behold, thou art bearing with no other person, but yet thou seest another law in thy members warring against the law of thy mind, and taking thee captive in the law of sin, which is in thy members. Cry aloud, then, and cry to God, that He may give thee peace from the inner strife: "O wretched man that I am, who shall deliver me from the body of this death? The grace of God through our Lord Jesus Christ."  Because, "He that followeth me," saith He, "shall not walk in darkness, but shall have the light of life." All strife ended, immortality shall follow; for "the last enemy, death, shall be destroyed." And what peace will this be? "This corruptible must put on incorruption, and this mortal must put on immortality."  To which that we may come (for it will then be in reality), let us now follow in hope Him who said, "I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life."
 Psalm 3:9.  2 Corinthians 5:6, 7.  Psalm 5:4.  Psalm 6:6.  Psalm 38:10.  1 Corinthians 2:9.  Matthew 11:29.  Psalm 116:16.  Psalm 46:8.  Psalm 85:11.  1 Corinthians 13:12.  1 John 3:2.  Galatians 5:17.  Romans 7:23-25.  1 Corinthians 15:26.
 2 Corinthians 5:6, 7.
 Psalm 5:4.
 Psalm 6:6.
 Psalm 38:10.
 1 Corinthians 2:9.
 Matthew 11:29.
 Psalm 116:16.
 Psalm 46:8.
 Psalm 85:11.
 1 Corinthians 13:12.
 1 John 3:2.
 Galatians 5:17.
 Romans 7:23-25.
 1 Corinthians 15:26.