1. Behold—calling attention, as to some wonderful exhibition, little as the world sees to admire. This verse is connected with the previous , thus: All our doing of righteousness is a mere sign that God, of His matchless love, has adopted us as children; it does not save us, but is a proof that we are saved of His grace.
what manner of—of what surpassing excellence, how gracious on His part, how precious to us.
love . . . bestowed—He does not say that God hath given us some gift, but love itself and the fountain of all honors, the heart itself, and that not for our works or efforts, but of His grace [LUTHER].
that—"what manner of love"; resulting in, proved by, our being, &c. The immediate effect aimed at in the bestowal of this love is, "that we should be called children of God."
should be called—should have received the privilege of such a glorious title (though seeming so imaginary to the world), along with the glorious reality. With God to call is to make really to be. Who so great as God? What nearer relationship than that of sons? The oldest manuscripts add, "And we ARE SO" really.
therefore—"on this account," because "we are (really) so."
us—the children, like the Father.
it knew him not—namely, the Father. "If they who regard not God, hold thee in any account, feel alarmed about thy state" [BENGEL]. Contrast 1 John 5:1. The world's whole course is one great act of non-recognition of God.

2. Beloved—by the Father, and therefore by me.
now—in contrast to "not yet." We now already are really sons, though not recognized as such by the world, and (as the consequence) we look for the visible manifestation of our sonship, which not yet has taken place.
doth not yet appear—Greek, "it hath not yet ('at any time,' Greek aorist) been visibly manifested what we shall be"—what further glory we shall attain by virtue of this our sonship. The "what" suggests a something inconceivably glorious.
but—omitted in the oldest manuscripts. Its insertion in English Version gives a wrong antithesis. It is not, "We do not yet know manifestly what . . . but we know," c. Believers have some degree of the manifestation already, though the world has not. The connection is, The manifestation to the world of what we shall be, has not yet taken place we know (in general; as a matter of well-assured knowledge; so the Greek) that when (literally, "if"; expressing no doubt as to the fact, but only as to the time; also implying the coming preliminary fact, on which the consequence follows, Malachi 1:6; John 14:3) He (not "it," namely, that which is not yet manifested [ALFORD]) shall be manifested (1 John 3:5; 1 John 2:28), we shall be like Him (Christ; all sons have a substantial resemblance to their father, and Christ, whom we shall be like, is "the express image of the Father's person," so that in resembling Christ, we shall resemble the Father). We wait for the manifestation (literally, the "apocalypse"; the same term as is applied to Christ's own manifestation) of the sons of God. After our natural birth, the new birth into the life of grace is needed, which is to be followed by the new birth into the life of glory; the two latter alike are termed "the regeneration" (1 John 2:28). The resurrection of our bodies is a kind of coming out of the womb of the earth, and being born into another life. Our first temptation was that we should be like God in knowledge, and by that we fell; but being raised by Christ, we become truly like Him, by knowing Him as we are known, and by seeing Him as He is [PEARSON, Exposition of the Creed]. As the first immortality which Adam lost was to be able not to die, so the last shall be not to be able to die. As man's first free choice or will was to be able not to sin, so our last shall be not to be able to sin [AUGUSTINE, The City of God, 22.30]. The devil fell by aspiring to God's power; man, by aspiring to his knowledge; but aspiring after God's goodness, we shall ever grow in His likeness. The transition from God the Father to "He," "Him," referring to Christ (who alone is ever said in Scripture to be manifested; not the Father, 1 John 2:28), implies the entire unity of the Father and the Son.
for, c.—Continual beholding generates likeness (1 John 2:28) as the face of the moon being always turned towards the sun, reflects its light and glory.
see him—not in His innermost Godhead, but as manifested in Christ. None but the pure can see the infinitely Pure One. In all these passages the Greek is the same verb opsomai; not denoting the action of seeing, but the state of him to whose eye or mind the object is presented; hence the Greek verb is always in the middle or reflexive voice, to perceive and inwardly appreciate [TITTMANN]. Our spiritual bodies will appreciate and recognize spiritual beings hereafter, as our natural bodies now do natural objects.

3. this hope—of being hereafter "like Him." Faith and love, as well as hope, occur in 1 John 3:11; 1 John 3:23.
in—rather, "(resting) upon Him"; grounded on His promises.
purifieth himself—by Christ's Spirit in him (John 15:5, end). "Thou purifiest thyself, not of thyself, but of Him who comes that He may dwell in thee" [AUGUSTINE]. One's justification through faith is presupposed.
as he is pure—unsullied with any uncleanness. The Second Person, by whom both the Law and Gospel were given.

4. Sin is incompatible with birth from God (1 John 3:1-3). John often sets forth the same truth negatively, which he had before set forth positively. He had shown, birth from God involves self-purification; he now shows where sin, that is, the want of self-purification, is, there is no birth from God.
Whosoever—Greek, "Every one who."
committeth sin—in contrast to 1 John 3:3, "Every man that hath this hope in Him purifieth himself"; and 1 John 3:3, "He that doeth righteousness."
transgresseth . . . the law—Greek, "committeth transgression of law." God's law of purity; and so shows he has no such hope of being hereafter pure as God is pure, and, therefore, that he is not born of God.
for—Greek, "and."
sin is . . . transgression of . . . law—definition of sin in general. The Greek having the article to both, implies that they are convertible terms. The Greek "sin" (hamartia) is literally, "a missing of the mark." God's will being that mark to be ever aimed at. "By the law is the knowledge of sin." The crookedness of a line is shown by being brought into juxtaposition with a straight ruler.

5. Additional proof of the incompatibility of sin and sonship; the very object of Christ's manifestation in the flesh was to take away (by one act, and entirely, aorist) all sins, as the scapegoat did typically.
and—another proof of the same.
in him is no sin—not "was," but "is," as in , "He is righteous," and , "He is pure." Therefore we are to be so.

6. He reasons from Christ's own entire separation from sin, that those in him must also be separate from it.
abideth in him—as the branch in the vine, by vital union living by His life.
sinneth not—In so far as he abides in Christ, so far is he free from all sin. The ideal of the Christian. The life of sin and the life of God mutually exclude one another, just as darkness and light. In matter of fact, believers do fall into sins (1 John 1:8-10; 1 John 2:1; 1 John 2:2); but all such sins are alien from the life of God, and need Christ's cleansing blood, without application to which the life of God could not be maintained. He sinneth not so long as he abideth in Christ.
whosoever sinneth hath not seen him—Greek perfect, "has not seen, and does not see Him." Again the ideal of Christian intuition and knowledge is presented (Matthew 7:23). All sin as such is at variance with the notion of one regenerated. Not that "whosoever is betrayed into sins has never seen nor known God"; but in so far as sin exists, in that degree the spiritual intuition and knowledge of God do not exist in him.
neither—"not even." To see spiritually is a further step than to know; for by knowing we come to seeing by vivid realization and experimentally.

7, 8. The same truth stated, with the addition that he who sins is, so far as he sins, "of the devil."
let no man deceive you—as Antinomians try to mislead men.
righteousness—Greek, "the righteousness," namely, of Christ or God.
he that doeth . . . is righteous—Not his doing makes him righteous, but his being righteous (justified by the righteousness of God in Christ, Romans 10:3-10) makes him to do righteousness: an inversion common in familiar language, logical in reality, though not in form, as in Luke 7:47; John 8:47. Works do not justify, but the justified man works. We infer from his doing righteousness that he is already righteous (that is, has the true and only principle of doing righteousness, namely, faith), and is therefore born of God (John 8:47); just as we might say, The tree that bears good fruit is a good tree, and has a living root; not that the fruit makes the tree and its root to be good, but it shows that they are so.
he—Christ.

8. He that committeth sin is of the devil—in contrast to "He that doeth righteousness," 1 John 3:7. He is a son of the devil (1 John 3:10; John 8:44). John does not, however, say, "born of the devil." as he does "born of God," for "the devil begets none, nor does he create any; but whoever imitates the devil becomes a child of the devil by imitating him, not by proper birth" [AUGUSTINE, Ten Homilies on the First Epistle of John, Homily 4.10]. From the devil there is not generation, but corruption [BENGEL].
sinneth from the beginning—from the time that any began to sin [ALFORD]: from the time that he became what he is, the devil. He seems to have kept his first estate only a very short time after his creation [BENGEL]. Since the fall of man [at the beginning of our world] the devil is (ever) sinning (this is the force of "sinneth"; he has sinned from the beginning, is the cause of all sins, and still goes on sinning; present). As the author of sin, and prince of this world, he has never ceased to seduce man to sin [LUECKE].
destroy—break up and do away with; bruising and crushing the serpent's head.
works of the devil—sin, and all its awful consequences. John argues, Christians cannot do that which Christ came to destroy.

9. Whosoever is born of God—literally, "Everyone that is begotten of God."
doth not commit sin—His higher nature, as one born or begotten of God, doth not sin. To be begotten of God and to sin, are states mutually excluding one another. In so far as one sins, he makes it doubtful whether he be born of God.
his seed—the living word of God, made by the Holy Spirit the seed in us of a new life and the continual mean of sanctification.
remaineth—abideth in him (compare Note, see on ; John 5:38). This does not contradict 1 John 1:8; 1 John 1:9; the regenerate show the utter incompatibility of sin with regeneration, by cleansing away every sin into which they may be betrayed by the old nature, at once in the blood of Christ.
cannot sin, because he is born of God—"because it is of God that he is born" (so the Greek order, as compared with the order of the same words in the beginning of the verse); not "because he was born of God" (the Greek is perfect tense, which is present in meaning, not aorist); it is not said, Because a man was once for all born of God he never afterwards can sin; but, Because he is born of God, the seed abiding now in Him, he cannot sin; so long as it energetically abides, sin can have no place. Compare Genesis 39:9, Joseph, "How CAN I do this great wickedness and sin against God?" The principle within me is at utter variance with it. The regenerate life is incompatible with sin, and gives the believer a hatred for sin in every shape, and an unceasing desire to resist it. "The child of God in this conflict receives indeed wounds daily, but never throws away his arms or makes peace with his deadly foe" [LUTHER]. The exceptional sins into which the regenerate are surprised, are owing to the new life principle being for a time suffered to lie dormant, and to the sword of the Spirit not being drawn instantly. Sin is ever active, but no longer reigns. The normal direction of the believer's energies is against sin; the law of God after the inward man is the ruling principle of his true self though the old nature, not yet fully deadened, rebels and sins. Contrast 1 John 5:18; John 8:34; compare Psalms 18:22; Psalms 18:23; Psalms 32:2; Psalms 32:3; Psalms 119:113; Psalms 119:176. The magnetic needle, the nature of which is always to point to the pole, is easily turned aside, but always reseeks the pole.

10. children of the devil—(See on 1 John 3:8; 1 John 3:8). There is no middle class between the children of God and the children of the devil.
doeth not righteousness—Contrast 1 John 3:8.
he that loveth not his brother— (1 John 4:8); a particular instance of that love which is the sum and fulfilment of all righteousness, and the token (not loud professions, or even seemingly good works) that distinguishes God's children from the devil's.

11. the message—"announcement," as of something good; not a mere command, as the law. The Gospel message of Him who loved us, announced by His servants, is, that we love the brethren; not here all mankind, but those who are our brethren in Christ, children of the same family of God, of whom we have been born anew.

12. who —not in the Greek.
of that wicked one—Translate, "evil one," to accord with "Because his own works were evil." Compare , "of the devil," in contrast to "of God," 1 John 3:10.
slew he him? Because his own works were evil, and his brother's righteous—through envy and hatred of his brother's piety, owing to which God accepted Abel's, but rejected Cain's offering. Enmity from the first existed between the seed of the woman and the seed of the serpent.

13. Marvel not—The marvel would be if the world loved you.
the world—of whom Cain is the representative (1 John 3:12).
hate you—as Cain hated even his own brother, and that to the extent of murdering him. The world feels its bad works tacitly reproved by your good works.

14. We—emphatical; hated though we be by the world, we know what the world knows not.
know—as an assured fact.
passed—changed our state. Colossians 1:13, "from the power of darkness . . . translated into the kingdom of His dear Son."
from death unto life—literally, "out of the death (which enthrals the unregenerate) into the life (of the regenerate)." A palpable coincidence of language and thought, the beloved disciple adopting his Lord's words.
because we love the brethren—the ground, not of our passing over out of death into life, but of our knowing that we have so. Love, on our part, is the evidence of our justification and regeneration, not the cause of them. "Let each go to his own heart; if he find there love to the brethren, let him feel assured that he has passed from death unto life. Let him not mind that his glory is only hidden; when the Lord shall come, then shall he appear in glory. For he has vital energy, but it is still wintertime; the root has vigor, but the branches are as it were dry; within there is marrow which is vigorous, within are leaves, within fruits, but they must wait for summer" [AUGUSTINE].
He that loveth not—Most of the oldest manuscripts omit "his brother," which makes the statement more general.
abideth—still.
in death—"in the (spiritual) death" (ending in eternal death) which is the state of all by nature. His want of love evidences that no saving change has passed over him.

15. hateth—equivalent to "loveth not" (1 John 3:14); there is no medium between the two. "Love and hatred, like light and darkness, life and death, necessarily replace, as well as necessarily exclude, one another" [ALFORD].
is a murderer—because indulging in that passion, which, if followed out to its natural consequences, would make him one. "Whereas, 1 John 3:14 desires us to lay down our lives for the brethren; duels require one (awful to say!) to risk his own life, rather than not deprive another of life" [BENGEL]. God regards the inward disposition as tantamount to the outward act which would flow from it. Whomsoever one hates, one wishes to be dead.
hath—Such a one still "abideth in death." It is not his future state, but his present, which is referred to. He who hates (that is, loveth not) his brother (1 John 3:14), cannot in this his present state have eternal life abiding in him.

16. What true love to the brethren is, illustrated by the love of Christ to us.
Hereby—Greek, "Herein."
the love of God —The words "of God" are not in the original. Translate, "We arrive at the knowledge of love"; we apprehend what true love is.
he—Christ.
and we—on our part, if absolutely needed for the glory of God, the good of the Church, or the salvation of a brother.
lives—Christ alone laid down His one life for us all; we ought to lay down our lives severally for the lives of the brethren; if not actually, at least virtually, by giving our time, care, labors, prayers, substance: Non nobis, sed omnibus. Our life ought not to be dearer to us than God's own Son was to Him. The apostles and martyrs acted on this principle.

17. this world's good—literally, "livelihood" or substance. If we ought to lay down our lives for the brethren (), how much more ought we not to withhold our substance?
seeth—not merely casually, but deliberately contemplates as a spectator; Greek, "beholds."
shutteth up his bowels of compassion —which had been momentarily opened by the spectacle of his brother's need. The "bowels" mean the heart, the seat of compassion.
how—How is it possible that "the love of (that is, 'to') God dwelleth (Greek, 'abideth') in him?" Our superfluities should yield to the necessities; our comforts, and even our necessaries in some measure, should yield to the extreme wants of our brethren. "Faith gives Christ to me; love flowing from faith gives me to my neighbor."

18. When the venerable John could no longer walk to the meetings of the Church but was borne thither by his disciples, he always uttered the same address to the Church; he reminded them of that one commandment which he had received from Christ Himself, as comprising all the rest, and forming the distinction of the new covenant, "My little children, love one another." When the brethren present, wearied of hearing the same thing so often, asked why he always repeated the same thing, he replied, "Because it is the commandment of the Lord, and if this one thing be attained, it is enough" [JEROME].
in word—Greek, "with word . . . with tongue, but in deed and truth."

19. hereby—Greek, "herein"; in our loving in deed and in truth ().
we know—The oldest manuscripts have "we shall know," namely, if we fulfil the command (1 John 3:18).
of the truth—that we are real disciples of, and belonging to, the truth, as it is in Jesus: begotten of God with the word of truth. Having herein the truth radically, we shall be sure not to love merely in word and tongue. (1 John 3:18).
assure—literally, "persuade," namely, so as to cease to condemn us; satisfy the questionings and doubts of our consciences as to whether we be accepted before God or not (compare Matthew 28:14; Acts 12:20, "having made Blastus their friend," literally, "persuaded"). The "heart," as the seat of the feelings, is our inward judge; the conscience, as the witness, acts either as our justifying advocate, or our condemning accuser, before God even now. Acts 12:20, has "conscience," but the passage is omitted in most old manuscripts. John nowhere else uses the term "conscience." Peter and Paul alone use it.
before him—as in the sight of Him, the omniscient Searcher of hearts. Assurance is designed to be the ordinary experience and privilege of the believer.

20. LUTHER and BENGEL take this verse as consoling the believer whom his heart condemns; and who, therefore, like Peter, appeals from conscience to Him who is greater than conscience. "Lord, Thou knowest all things: thou knowest that I love Thee." Peter's conscience, though condemning him of his sin in denying the Lord, assured him of his love; but fearing the possibility, owing to his past fall, of deceiving himself, he appeals to the all-knowing God: so Paul, 1 Corinthians 4:3; 1 Corinthians 4:4. So if we be believers, even if our heart condemns us of sin in general, yet having the one sign of sonship, love, we may still assure our hearts (some oldest manuscripts read heart, 1 Corinthians 4:4, as well as 1 John 3:20), as knowing that God is greater than our heart, and knoweth all things. But thus the same Greek is translated "because" in the beginning, and "(we know) that" in the middle of the verse, and if the verse were consolatory, it probably would have been, "Because EVEN if our heart condemn us," c. Therefore translate, "Because (rendering the reason why it has been stated in 1 John 3:20 to be so important to 'assure our hearts before Him') if our heart condemn (Greek, 'know [aught] against us' answering by contrast to 'we shall know that we are of the truth') us (it is) because God is greater than our heart and knoweth all things." If our heart judges us unfavorably, we may be sure that He, knowing more than our heart knows, judges us more unfavorably still [ALFORD]. A similar ellipsis ("it is") occurs in 1 Corinthians 14:27; 2 Corinthians 1:6; 2 Corinthians 8:23. The condemning testimony of our conscience is not alone, but is the echo of the voice of Him who is greater and knoweth all things. Our hypocrisy in loving by word and tongue, not in deed and truth, does not escape even our conscience, though weak and knowing but little, how much less God who knows all things! Still the consolatory view may be the right one. For the Greek for "we shall assure our hearts" (see on 2 Corinthians 8:23), is gain over, persuade so as to be stilled, implying that there was a previous state of self-condemnation by the heart (1 John 3:20), which, however, is got over by the consolatory thought, "God is greater than my heart" which condemns me, and "knows all things" (Greek "ginoskei," "knows," not "kataginoskei," "condemns"), and therefore knows my love and desire to serve Him, and knows my frame so as to pity my weakness of faith. This gaining over the heart to peace is not so advanced a stage as the having CONFIDENCE towards God which flows from a heart condemning us not. The first "because" thus applies to the two alternate cases, 1 John 3:20; 1 John 3:21 (giving the ground of saying, that having love we shall gain over, or assure our minds before Him, 1 John 3:21); the second "because" applies to the first alternate alone, namely, "if our heart condemn us." When he reaches the second alternate, 1 John 3:21, he states it independently of the former "because" which had connected it with 1 John 3:21, inasmuch as CONFIDENCE toward God is a farther stage than persuading our hearts, though always preceded by it.

21. Beloved—There is no "But" contrasting the two cases, 1 John 3:20; 1 John 3:21, because "Beloved" sufficiently marks the transition to the case of the brethren walking in the full confidence of love (1 John 3:21). The two results of our being able to "assure our hearts before Him" (1 John 3:19), and of "our heart condemning us not" (of insincerity as to the truth in general, and as to LOVE in particular) are, (1) confidence toward God; (2) a sure answer to our prayers. John does not mean that all whose hearts do not condemn them, are therefore safe before God; for some have their conscience seared, others are ignorant of the truth, and it is not only sincerity, but sincerity in the truth which can save men. Christians are those meant here: knowing Christ's precepts and testing themselves by them.

22. we receive—as a matter of fact, according to His promise. Believers, as such, ask only what is in accordance with God's will; or if they ask what God wills not, they bow their will to God's will, and so God grants them either their request, or something better than it.
because we keep his commandments—Compare Psalms 66:18; Psalms 34:15; Psalms 145:18; Psalms 145:19. Not as though our merits earned a hearing for our prayers, but when we are believers in Christ, all our works of faith being the fruit of His Spirit in us, are "pleasing in God's sight"; and our prayers being the voice of the same Spirit of God in us, naturally and necessarily are answered by Him.

23. Summing up of God's commandments under the Gospel dispensation in one commandment.
this is his commandment—singular: for faith and love are not separate commandments, but are indissolubly united. We cannot truly love one another without faith in Christ, nor can we truly believe in Him without love.
believe—once for all; Greek aorist.
on the name of his Son—on all that is revealed in the Gospel concerning Him, and on Himself in respect to His person, offices, and atoning work.
as he—as Jesus gave us commandment.

24. dwelleth in him—The believer dwelleth in Christ.
and he in him—Christ in the believer. Reciprocity. "Thus he returns to the great keynote of the Epistle, abide in Him, with which the former part concluded" (1 John 2:28).
hereby—herein we (believers) know that he abideth in us, namely, from (the presence in us of) the Spirit "which He hath given us." Thus he prepares, by the mention of the true Spirit, for the transition to the false "spirit," 1 John 2:28; after which he returns again to the subject of love.