Dearly beloved, I write not a new commandment to you, but an old commandment which you had from the beginning. The old commandment is the word which you have heard.

“"Dearly beloved, I write unto you no new commandment, but the old commandment which ye had from the beginning." What commandment calls he "old"? "Which ye had," saith he, "from the beginning. Old" then, in this regard, that ye have already heard it: otherwise he will contradict the Lord, where He saith, "A new commandment give I unto you, that ye love one another." But why an "old" commandment? Not as pertaining to the old man. But why? "Which ye had from the beginning. The old commandment is the word which ye have heard." Old then, in this regard, that ye have already heard it. And the selfsame he showeth to be new, saying, "Again, a new commandment write I unto you." Not another, but the selfsame which he hath called old, the same is also new. Why? "Which thing is true in Him and in you." Why old, ye have already heard: that is, because ye knew it already. But why new? "Because the darkness is past, and the true light now shineth." Lo, whence it is new: because the darkness pertains to the old man, but the light to the new man. What saith the Apostle Paul? "Put ye off the old man, and put ye on the new." And again what saith he? "Ye were sometime darkness, but now light in the Lord."”

“The seventh verse may be supposed either to look backward to what immediately preceded (and then it is walking as Christ walked that is here represented as no new, but an old commandment; it is that which the apostles would certainly inculcate wherever they brought Christ's gospel), or to look forward to what the apostle is now going to recommend, and that is the law of fraternal love; this is the message heard from the beginning (Jo1 3:11), and the old commandment, Jo2 1:5. Now, while the apostle addresses himself to the recommendation of such a practice, he is ready to give an instance thereof in his affectionate appellation: "Brethren, you who are dear to me in the bond of that love to which I would solicit you;" and so the precept of fraternal love is recommended, I. As an old one: I write no new commandment unto you, but an old commandment, which you had from the beginning, Jo1 2:7. The precept of love must be as old as human nature; but it might admit divers enactions, enforcements, and motives. In the state of innocence, had human nature then been propagated, men must have loved one another as being of one blood, made to dwell on the earth, as being God's offspring, and bearing his image. In the state of sin and promised recovery, they must love one another as related to God their Maker, as related to each other by blood, and as partners in the same hope. When the Hebrews were peculiarly incorporated, they must accordingly love each other, as being the privileged people, whose were the covenants and the adoption, and of whose race the Messiah and head of the church must spring; and the law of love must be conveyed with new obligations to the new Israel of God, to the gospel church, and so it is the old commandment, or the word which the children of the gospel Israel have heard from the beginning, Jo1 2:7. II. As a new one: "Again, to constrain you to this duty the more, a new commandment I write unto you, the law of the new society, the Christian corporation, which thing is true in him, the matter of which was first true in and concerning the head of it; the truth of it was first and was abundantly in him; he loved the church, and gave himself for it: and it is true in you; this law is in some measure written upon your hearts; you are taught of God to love one another, and that because" (or since, or forasmuch as) "the darkness is past, the darkness of your prejudiced unconverted (whether Jewish or Gentile) minds, your deplorable ignorance of God and of Christ is now past, and the true light now shineth (Jo1 2:8); the light of evangelical revelation hath shone with life and efficacy into your hearts; hence you have seen the excellency of Christian love, and the fundamental obligation thereto." Hence we see that the fundamentals (and particularly the fundamental precepts) of the Christian religion may be represented either as new or old; the reformed doctrine, or doctrine of religion in the reformed churches, is new and old - new, as taught after long darkness, by the lights of the reformation, new as purged from the adulterations of Rome; but old as having been taught and heard from the beginning. We should see that that grace or virtue which was true in Christ be true also in us; we should be conformable to our head. The more our darkness is past, and gospel light shines unto us, the deeper should our subjection be to the commandments of our Lord, whether considered as old or new. Light should produce a suitable heat. Accordingly, here is another trial of our Christian light; before, it was to be approved by obedience to God; here by Christian love. 1. He who wants such love in vain pretends his light: He that saith he is in the light, and hateth his brother, is in darkness even unto now, Jo1 2:9. It is proper for sincere Christians to acknowledge what God has done for their souls; but in the visible church there are often those who assume to themselves more than is true, there are those who say they are in the light, the divine revelation has made its impression upon their minds and spirits, and yet they walk in hatred and enmity towards their Christian brethren; these cannot be swayed by the sense of the love of Christ to their brethren, and therefore remain in their dark state, notwithstanding their pretended conversion to the Christian religion. 2. He who is governed by such love approves his light to be good and genuine: He that loveth his brother (as his brother in Christ) abideth in the light, Jo1 2:10. He sees the foundation and reason of Christian love; he discerns the weight and value of the Christian redemption; he sees how meet it is that we should love those whom Christ hath loved; and then the consequence will be that there is no occasion of stumbling in him (Jo1 2:10); he will be no scandal, no stumbling-block, to his brother; he will conscientiously beware that he neither induce his brother to sin nor turn him out of the way of religion, Christian love teaches us highly to value our brother's soul, and to dread every thing that will be injurious to his innocence and peace. 3. Hatred is a sign of spiritual darkness: But he that hateth his brother is in darkness, Jo1 2:11. Spiritual light is instilled by the Spirit of grace, and one of the first-fruits of that Spirit is love; he then who is possessed with malignity towards a Christian brother must needs be destitute of spiritual light; consequently he walks in darkness (Jo1 2:11); his life is agreeable to a dark mind and conscience, and he knows not whither he goes; he sees not whither this dark spirit carries him, and particularly that it will carry him to the world of utter darkness, because darkness hath blinded his eyes, Jo1 2:11. The darkness of regeneracy, evidenced by a malignant spirit, is contrary to the light of life; where that darkness dwells, the mind, the judgment, and the conscience will be darkened, and so will mistake the way to heavenly endless life. Here we may observe how effectually our apostle is now cured of his once hot and flaming spirit. Time was when he was for calling for fire from heaven upon poor ignorant Samaritans who received them not, Luk 9:54. But his Lord had shown him that he knew not his own spirit, nor whither it led him. Having now imbibed more of the Spirit of Christ, he breathes out good-will to man, and love to all the brethren. It is the Lord Jesus that is the great Master of love: it is his school (his own church) that is the school of love. His disciples are the disciples of love, and his family must be the family of love.”

“Brethren, I write no new commandment unto you,.... Some understand this of faith, which this apostle calls a commandment, Jo1 3:23; but it rather intends the commandment of love, especially to the brethren, of which the apostle says the same things as here in his second epistle, Jo1 2:5; and this sense agrees both with what goes before and follows after, and is a considerable branch of the commandments of Christ to be kept, and of walking as he walked; and the word "brethren", prefixed to this account, may direct to, and strengthen this sense, though the Vulgate Latin and Syriac versions read, "beloved"; and so the Alexandrian copy, and others: and this commandment is said to be not a new one, but an old commandment, which ye had from the beginning; it being in its original a part of the eternal law of truth, founded upon the unalterable nature and eternal will of God, who is love itself, and requires it in all his creatures; being what was written on Adam's heart in a state of innocence, and a branch of the divine image stamped upon him; and is what was delivered in the law of Moses, for love to God and men is the sum and substance of that; and was taught by Christ and his apostles from the beginning of the Gospel dispensation; and was what these saints had been acquainted with, and influentially instructed in from their first conversion, being taught of God in regeneration to love one another; so that this was no novel doctrine, no upstart notion, no new law, but of the greatest and most venerable antiquity, and therefore to be regarded in the most respectful manner. The old commandment is the word which ye have heard from the beginning; or this ancient law of love is contained in, and enforced by that word or doctrine which was delivered from the beginning of time; and which these saints had heard of, concerning the seed of the woman's bruising the serpent's head, which includes the work of redemption and salvation by Christ, atonement by his sacrifice, forgiveness of sin through his blood, and justification by his righteousness, than which nothing can more powerfully engage to love God, and Christ, and one another; and which is also strongly encouraged by the word of God and Gospel of Christ, which they had heard, and had a spiritual and saving knowledge of, from the time they were effectually called by the grace of God: the phrase, "from the beginning", is left out in the Alexandrian copy, and others, and in the Vulgate Latin, Syriac, and Ethiopic versions; it is omitted in both clauses of the text in the latter.”

“Brethren, I write no new commandment - There seems a contradiction between this and the next verse. But the apostle appears to speak, not so much of any difference in the essence of the precept itself, as in reference to the degrees of light and grace belonging to the Mosaic and Christian dispensations. It was ever the command of God that men should receive his light, walk by that light, and love him and one another. But this commandment was renewed by Christ with much latitude and spirituality of meaning; and also with much additional light to see its extent, and grace to observe it. It may therefore be called the Old commandment, which was from the beginning; and also a New commandment revealed afresh and illustrated by Christ, with the important addition to the meaning of Thou shalt love thy neighbor as thyself, ye shall love the brethren so as to lay down your lives for each other. See the note on Joh 13:34. Instead of αδελφοι, brethren, ABC, thirteen others, with both the Syriac, Erpen's Arabic, Coptic, Sahidic, Armenian, Slavonic, and Vulgate, with several of the fathers, have αγαπητοι, beloved. This is without doubt the true reading.”

“An old commandment…. and again, a new commandment. He means the commandment of charity, or of the love of God and the love of our neighbour. This he calls both an old and a new precept. It may be called old, not only as being a precept of the law of nature, and always obligatory, but because St. John and the other apostles had delivered it to them long ago, i.e. when these persons were first converted. It may also be called a new precept, St. John recommending it anew to them in this epistle, and declaring it to be enjoined in a particular manner by our Saviour Christ, after it had been misconstrued and neglected, especially as it regards our neighbour, that is, every one without exception; so that if any one hate another, it is in vain that he pretends to walk in the light of the gospel. (Witham) — A new commandment; viz. the commandment of love, which was given in the old law, but was renewed and extended by Christ. See John xiii. 33. (Challoner)”

“Brethren--The oldest manuscripts and versions read instead, "Beloved," appropriate to the subject here, love. no new commandment--namely, love, the main principle of walking as Christ walked (Jo1 2:6), and that commandment, of which one exemplification is presently given, Jo1 2:9-10, the love of brethren. ye had from the beginning--from the time that ye first heard the Gospel word preached.”