For you were heretofore darkness, but now light in the Lord. Walk then as children of the light.

“As, then, those who have shaken off sleep forthwith become all awake within; or rather, as those who try to remove a film that is over the eyes, do not supply to them from without the light which they do not possess, but removing the obstacle from the eyes, leave the pupil free; thus also we who are baptized, having wiped off the sins which obscure the light of the Divine Spirit, have the eye of the spirit free, unimpeded, and full of light, by which alone we contemplate the Divine, the Holy Spirit flowing down to us from above. This is the eternal adjustment of the vision, which is able to see the eternal light, since like loves like; and that which is holy, loves that from which holiness proceeds, which has appropriately been termed light. "Once ye were darkness, now are ye light in the Lord." Hence I am of opinion man was called by the ancients φώς. But he has not yet received, say they, the perfect gift. I also assent to this; but he is in the light, and the darkness comprehendeth him not.”

“Observe how wisely he urges them forward; first, from the thought of Christ, that ye love one another, and do injury to no man; then, on the other hand, from the thought of punishment and hell-fire. "For ye were once darkness," says he, "but are now light in the Lord." Which is what he says also in the Epistle to the Romans; "What fruit then had ye at that time in the things whereof ye are now ashamed?" (Rom. vi. 21), and reminds them of their former wickedness. That is to say, thinking what ye once were, and what ye are now become, do not run back into your former wickedness, nor do "despite to the grace" (Heb. x. 29) of God. "Ye were once darkness, but are now light in the Lord!" Not, he says, by your own virtue, but through the grace of God has this accrued to you. That is to say, ye also were sometime worthy of the same punishments, but now are so no more. "Walk" therefore "as children of light." What is meant however by "children of light," he adds afterwards.”

“Above, the Apostle forbade carnal sins, threatening punishment and removing the deception; here he assigns a reason taken from their condition, and he does two things. For first he sets forth their condition; second he draws two conclusions from these, at the place "that you may be children of light," etc. Now he sets down two conditions: first the past one, second the present condition, at "but now light," etc. He says therefore, "you were at one time darkness," that is, blinded by ignorance and error. Above, IV, 18: "having their understanding darkened with darkness." Ps. 81:5: "They have not known, nor understood; they walk in darkness." Likewise, dark through sin. Prov. 4:12: "The way of the wicked is darksome; they know not where they fall." But it should be noted that he does not indefinitely say "darksome," but "darkness"; because just as anyone seems to be what predominates in him — just as the whole city seems to be the king, and what the king does is said to be done by the city — so when sin reigns in a man, then the whole man is called sin and darkness. There follows, "but now light," etc., where he sets down the present condition; as if to say: but now you have the light of faith. Phil. 2:15: "Among whom you shine as lights in the world." Matt. 5:14: "You are the light of the world." But against this it is said of John the Baptist: "he was not the light"; how then are the other faithful called light? I respond: they are not called light by essence, but by participation. Then, when he says "walk then as children of light," etc., he draws two conclusions. For he had said that they had been darkness and that now they are light. And therefore first he concludes that they should conform themselves to what they now are; second, that they should avoid what they formerly were, at "and have no fellowship," etc. The first is divided into two. First he sets down the admonition; second he expounds it, at "for the fruit of the light," etc. He says therefore: because you are now light, you should do the works of light; therefore "walk as children of light." John 12:35: "Walk whilst you have the light," etc. Now he expounds this when he says "for the fruit," etc. Now one walks as a child of light in two ways: first as to the substance, or genus, of the work; second as to the manner, or the intention of the one doing it. First, therefore, he sets down the works which must be done; second, with what intention they ought to be done, at "proving," etc. He says therefore: I have said that you should walk as children of light; now the fruit of light are works that are fruitful and clear. Ecclesiasticus 24:23: "My flowers are the fruit of honor," etc. And this "in all goodness," etc. Where it should be noted that every act of virtue is reduced to three things. For it is necessary that the agent be ordered in himself, toward his neighbor, and toward God. In himself, that he be good in himself, and for this reason he says "in all goodness." Ps. 118:66: "Teach me goodness and discipline and knowledge," etc. Likewise, toward the neighbor through justice; therefore he says "in justice." Ps. 118:121: "I have done judgment and justice," etc. Toward God through knowledge and confession of the truth, and therefore he says "and truth." Zach. 8:19: "For love ye truth and peace." Or otherwise, so that goodness is referred to the heart, justice to the deed, truth to the mouth. Above, IV, 25, and Zach. 8:16: "Speak ye truth every one with his neighbor." Then, when he says "proving," etc., he shows with what intention they ought to work: namely, not abruptly, but "proving," that is, discerning by reason. "Let every one prove his own work," as is said in Gal. 6:4. And this, "what is well-pleasing to God," that is, that you intend to do what pleases God. Rom. 15: "that you may prove what is the good, and the acceptable, and the perfect will of God." Then, when he says "and have no fellowship," etc., he exhorts them not to return to the state which they had left, because, as is said in Gal. 2:18: "For if I build up again the things which I have destroyed, I make myself a prevaricator"; 2 Peter 2:22: "The dog is returned to his vomit, and the sow that was washed to her wallowing in the mire." Now this part is divided into two. First he sets down the admonition; second he assigns the reason, at "for the things that are done by them in secret," etc. The first is again divided into two. First he admonishes them not to do evil; second, that they reprove evils, at "but rather reprove them," etc. He says therefore, "proving what is well-pleasing to God," "and have no fellowship with the unfruitful works of darkness," that is, with carnal works leading to perpetual darkness; which indeed are unfruitful, because they have only a momentary delight, most swiftly passing away. Rom. 6:21: "What fruit therefore had you then in those things, of which you are now ashamed?" Jude 1:12: "Trees of autumn, unfruitful, twice dead, plucked up by the roots, raging waves of the sea, foaming out their own confusion," etc. Likewise, they seek dark places on account of shamefulness, because in them they associate with brute beasts. Job 24:15: "The eye of the adulterer observeth darkness, saying: No eye shall see me; and he covereth his face. In the dark he diggeth through houses," etc. Therefore have no fellowship with these, by imitating, by helping, by consenting. Ecclesiasticus 13:22: "What fellowship hath a holy man with a dog?" But certainly this does not suffice, unless you also reprove them, because, as Augustine says, sometimes God punishes the innocent who associate with them, because some good men do not reprove the evil. Ecclesiasticus 17:12: "And he gave to every one of them commandment concerning his neighbor." And therefore he says "but rather reprove." 2 Tim. 4:2: "Reprove, entreat, rebuke," etc. But do we always sin if we do not reprove? Augustine responds: for what you do not reprove out of the fear of charity — namely, lest he become worse, and being scandalized, afflict the good — you do not sin. But if out of the fear of cupidity — namely, lest he become indignant and you lose his benefits to you — then you sin.”

“For the fruit of the Spirit,.... Either of the spirit of man, as renewed, or rather of the Spirit of God; the allusion is to fruits of trees: the believer is a tree of righteousness; Christ is his root; the Spirit is the sap, which supports and nourishes; and good works, under the influence of his grace, are the fruit: the Alexandrian copy, and some others, and the Vulgate Latin, Syriac, and Ethiopic versions, read "the fruit of light"; which agrees with the preceding words: and the genuine fruit of internal grace, or light, is in all goodness, and righteousness, and truth; the fruit of "goodness", lies in sympathizing with persons in distress; in assisting such according to the abilities men have in a readiness to forgive offences and injuries; and in using meekness and candour in admonishing others: "righteousness" lies in living in obedience to the law of God; in attending the worship and service of him; and in discharging our duty to our fellow creatures; and this as goodness, is very imperfect, and not to be boasted of, or trusted to, nor is salvation to be expected from it: "truth" is opposed to lying, to hypocrisy, to error and falsehood; and where the Spirit of God, and the work of grace are, there will be more or less an appearance of these fruits.”

“For ye were sometimes (ποτε, formerly) darkness - While ye lived in darkness, ye lived in these crimes. But now are ye light in the Lord - When ye were in heathenish darkness ye served divers lusts and pleasures, but now ye have the light - the wisdom and teaching which come from God; therefore walk as children of the light - let the world see that ye are not slaves to the flesh, but free, willing, rational servants of the Most High; not brutish followers of devil gods.”

“sometimes--"once." The emphasis is on "were." Ye ought to have no fellowship with sin, which is darkness, for your state as darkness is now PAST. Stronger than "in darkness" (Rom 2:19). light--not merely "enlightened"; but light enlightening others (Eph 5:13). in--in union with the Lord, who is THE LIGHT. children of light--not merely "of the light"; just as "children of disobedience" is used on the opposite side; those whose distinguishing characteristic is light. PLINY, a heathen writing to Trajan, bears unwilling testimony to the extraordinary purity of Christians' lives, contrasted with the people around them.”