The Meaning of 1 John 2:5 Explained

1 John 2:5

KJV: But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.

YLT: and whoever may keep his word, truly in him the love of God hath been perfected; in this we know that in him we are.

Darby: but whoever keeps his word, in him verily the love of God is perfected. Hereby we know that we are in him.

ASV: but whoso keepeth his word, in him verily hath the love of God been perfected. Hereby we know that we are in him:

KJV Reverse Interlinear

But  whoso  keepeth  his  word,  in  him  verily  is  the love  of God  perfected:  hereby  know we  that  we are  in  him. 

What does 1 John 2:5 Mean?

Study Notes

perfect
.
The word implies full development, growth into maturity of godliness, not sinless perfection. Ephesians 4:12 ; Ephesians 4:13 . In this passage the Father's kindness, not His sinlessness, is the point in question. Luke 6:35 ; Luke 6:36

Verse Meaning

On the other hand the Christian who is careful to observe all of God"s Word (not just His commandments, 1 John 2:4) gives evidence that he has come to understand and appreciate God"s love for him. God"s love is perfected in him in the sense that the Christian has perceived it, has responded to it, and it is having its intended effect in his or her behavior. Our love for God is in view here rather than His love for us (cf. 1 John 2:15; 1 John 4:12; 1 John 5:3). [1] Loving God is parallel to knowing God ( 1 John 2:3-4).
Bible students have often called John the apostle of love because of his frequent references to love. There are no fewer than46 references to love in1John. The verb agapao appears28 times in these verses: 1 John 2:10; 1 John 2:15 (twice); 1 John 3:10-11; 1 John 3:14 (twice), 18 , 23; 1 John 4:7 (twice), 8 , 10 (twice), 11 (twice), 12 , 19 (twice), 20 (thrice), 21 (twice); 1 John 5:1 (twice), 2 (twice). The noun agape occurs18 times: 1 John 2:5; 1 John 2:15; 1 John 3:1; 1 John 3:16-17; 1 John 4:7-10; 1 John 4:12; 1 John 4:16 (thrice), 17 , 18 (thrice); 1 John 5:3. Likewise many have referred to Paul as the apostle of faith and to Peter as the apostle of hope because of their major emphases.

Context Summary

1 John 2:1-11 - Keeping His Commandment Of Love
It is clearly possible to be kept from known and presumptuous sin. We shall be tempted, for that is an inevitable experience of life in this world; but we may be perfectly kept by the indwelling Spirit. Yet if we should be overtaken by some sudden gust of temptation, let us not despair; our Advocate ever makes intercession for us. The evidence that we have a saving knowledge of our Savior is obtained, not by the memory of a rapturous experience, but because we are conscious of doing, for His sake, things which we should otherwise evade. Let us continue to do such things, because by the path of patient obedience we shall enter into the Paradise of perfect, love. The outer walk is the best evidence to ourselves and others that there is an abiding union between us and Jesus. Light involves love; and love, light. Love and you are in light. Indulge hatred or ill-will and you begin to grope in darkness. [source]

Chapter Summary: 1 John 2

1  He comforts them against the sins of infirmity
3  Rightly to know God is to keep his commandments;
9  to love our brothers;
15  and not to love the world
18  We must beware of antichrists;
20  from whose deceits the godly are safe, preserved by perseverance in faith, and holiness of life

Greek Commentary for 1 John 2:5

But whoso keepeth [ος δ αν τηρηι]
Indefinite relative clause with modal αν — an and the present active subjunctive, “whoever keeps on keeping.” [source]
Verily [αλητως]
Truly, of a truth. This prize is open to all, not confined to a few initiated Gnostic intellectuals or pneumatics. Hath the love of God been perfected (η αγαπη του τεου τετελειωται — hē agapē tou theou teteleiōtai). Perfect passive indicative of τελειοω — teleioō stands completed. Probably objective genitive, our love for God, which is realized in absolute obedience (Brooke). Hereby That is by continuous keeping of Christ‘s commandments, not by loud talk and loose living. [source]
Hath the love of God been perfected [η αγαπη του τεου τετελειωται]
Perfect passive indicative of τελειοω — teleioō stands completed. Probably objective genitive, our love for God, which is realized in absolute obedience (Brooke). [source]
Hereby [εν τουτωι]
That is by continuous keeping of Christ‘s commandments, not by loud talk and loose living. [source]
We are in Him []
Compare Acts 17:28. See note on 1 John 2:15. [source]
Keepeth His word [τηρῇ αὐτοῦ τὸν λόγον]
Note the changed phrase: word for commandments. The word is the revelation regarded as a whole, which includes all the separate commandments or injunctions. See the use of λόγος word, and ἐντολή preceptin John 14:21-24. [source]
Is the love of God perfected [ἡ ἀγάπη τοῦ Θεοῦ τετελείωται]
Rev., rendering the perfect tense more closely, hath the love of God been perfected. The change in the form of this antithetic clause is striking. He who claims to know God, yet lives in disobedience, is a liar. We should expect as an offset to this: He that keepeth His commandments is of the truth; or, the truth is in him. Instead we have, “In him has the love of God been perfected.” In other words, the obedient child of God is characterized, not by any representative trait or quality of his own personality, but merely as the subject of the work of divine love: as the sphere in which that love accomplishes its perfect work. The phrase ἡ ἀγάπη τοῦ Θεοῦ the love of God, may mean either the love which God shows, or the love of which God is the object, or the love which is characteristic of God whether manifested by Himself or by His obedient child through His Spirit. John's usage is not decisive like Paul's, according to which the love of God habitually means the love which proceeds from and is manifested by God. The exact phrase, the love of God or the love of the Father, is found in 1 John 3:16; 1 John 4:9, in the undoubted sense of the love of God to men. The same sense is intended in 1 John 3:1, 1 John 3:9, 1 John 3:16, though differently expressed. The sense is doubtful in 1 John 2:5; 1 John 3:17; 1 John 4:12. Men's love to God is clearly meant in 1 John 2:15; 1 John 5:3. The phrase occurs only twice in the Gospels (Luke 6:42; John 5:42), and in both cases the sense is doubtful. Some, as Ebrard, combine the two, and explain the love of God as the mutual relation of love between God and men. It is not possible to settle the point decisively, but I incline to the view that the fundamental idea of the love of God as expounded by John is the love which God has made known and which answers to His nature. In favor of this is the general usage of ἀγάπη lovein the New Testament, with the subjective genitive. The object is more commonly expressed by εἰς towardsor to. See 1 Thessalonians 3:12; Colossians 1:4; 1 Peter 4:8. Still stronger is John's treatment of the subject in ch. 4. Here we have, 1 John 4:9, the manifestation of the love of God in us ( ἐν ἡμῖν ) By our life in Christ and our love to God we are a manifestation of God's love. Directly following this is a definition of the essential nature of love. “In this is love; i.e., herein consists love: not that we have loved God, but that He loved us ” (1 John 4:10). Our mutual love is a proof that God dwells in us. God dwelling in us, His love is perfected in us (1 John 4:12). The latter clause, it would seem, must be explained according to 1 John 4:10. Then (1 John 4:16), “We have known and believed the love that God hath in us ” (see on John 16:22, on the phrase have love ). “God is love;” that is His nature, and He imparts this nature to be the sphere in which His children dwell. “He that dwelleth in love dwelleth in God.” Finally, our love is engendered by His love to us. “We love Him because He first loved us” (1 John 4:19). -DIVIDER-
-DIVIDER-
In harmony with this is John 15:9. “As the Father loved me, I also loved you. Continue ye in my love.” My love must be explained by I loved you. This is the same idea of divine love as the sphere or element of renewed being; and this idea is placed, as in the passage we are considering, in direct connection with the keeping of the divine commandments. “If ye keep my commandments ye shall abide in my love.”-DIVIDER-
This interpretation does not exclude man's love to God. On the contrary, it includes it. The love which God has, is revealed as the love of God in the love of His children towards Him, no less than in His manifestations of love to them. The idea of divine love is thus complex. Love, in its very essence, is reciprocal. Its perfect ideal requires two parties. It is not enough to tell us, as a bare, abstract truth, that God is love. The truth must be rounded and filled out for us by the appreciable exertion of divine love upon an object, and by the response of the object. The love of God is perfected or completed by the perfect establishment of the relation of love between God and man. When man loves perfectly, his love is the love of God shed abroad in his heart. His love owes both its origin and its nature to the love of God. -DIVIDER-
-DIVIDER-
The word verily ( ἀληθῶς ) is never used by John as a mere formula of affirmation, but has the meaning of a qualitative adverb, expressing not merely the actual existence of a thing, but its existence in a manner most absolutely corresponding to ἀλήθεια truthCompare John 1:48; John 8:31. Hath been perfected. John is presenting the ideal of life in God. “This is the love of God that we keep His commandments.” Therefore whosoever keepeth God's word, His message in its entirety, realizes the perfect relation of love. [source]

Reverse Greek Commentary Search for 1 John 2:5

John 4:34 Finish [πελειώσω]
Better, as Rev., accomplish. Not merely bring to an end, but perfect. From τέλειος , perfect. The verb is characteristic of John, and of the Epistle to the Hebrews. See John 5:36; John 17:4; John 19:28; 1 John 2:5; 1 John 4:12; Hebrews 2:10; Hebrews 5:9, etc. [source]
John 16:30 By this [ἐν τούτῳ]
Literally, in this. Compare 1 John 2:3, 1 John 2:5; 1 John 3:16, 1 John 3:19, 1 John 3:24; 1 John 4:9, 1 John 4:10, 1 John 4:13, 1 John 4:17; 1 John 5:2. [source]
John 14:15 If ye love me [εαν αγαπατε με]
Third-class condition “if ye keep on loving (present active subjunctive, same contract form as indicative) me.” Cf. John 14:23. Ye will keep Future active of τηρεω — tēreō not aorist imperative τηρησατε — tērēsate (keep) as some MSS. have. For this phrase see also John 8:51; John 14:23, John 14:24; John 15:20; 1 John 2:5. Continued love prevents disobedience. [source]
John 5:42 But I know you [αλλα εγνωκα υμας]
Perfect active indicative of γινωσκω — ginōskō “I have come to know and still know,” the knowledge of personal experience (John 2:24.). The love o‘ God Objective genitive, “the love toward God.” See Luke 11:42 for this phrase in the same sense (only other instance in the Gospels, but common in 1John (1 John 2:5; 1 John 3:17; 1 John 4:7, 1 John 4:9; 1 John 5:3) and in 2 Thessalonians 3:5; 2 Corinthians 13:14; Romans 5:5. The sense of God‘s love for man occurs in 1 John 3:1; 1 John 4:9, 1 John 4:10, 1 John 4:16; John 15:9. of Christ‘s love for man. These rabbis did not love God and hence did not love Christ. [source]
John 8:51 If a man keep my word [εαν τις τον εμον λογον τηρησηι]
Condition of third class with εαν — ean and constative aorist active subjunctive of τηρεω — tēreō Repeated in John 8:52. See John 8:43 about hearing the word of Christ. Common phrase in John (John 8:51, John 8:52, John 8:55; John 14:23, John 14:24; John 15:20; John 17:6; 1 John 2:5). Probably the same idea as keeping the commands of Christ (John 14:21). He shall never see death Spiritual death, of course. Strong double negative ου μη — ou mē with first aorist active subjunctive of τεωρεω — theōreō The phrase “see death” is a Hebraism (Psalm 89:48) and occurs with ιδειν — idein (see) in Luke 2:26; Hebrews 11:5. No essential difference meant between οραω — horaō and τεωρεω — theōreō See John 14:23 for the blessed fellowship the Father and the Son have with the one who keeps Christ‘s word. [source]
1 Corinthians 8:3 The same is known of Him [οὗτος ἔγνωσται ὑπ ' αὐτοῦ]
The same, i.e., this same man who loves God. He does not say knows God, but implies this in the larger truth, is known by God. Compare Galatians 4:9; 1 John 4:7, 1 John 4:8, 1 John 4:16; 2 Timothy 2:19. Γινώσκω in New-Testament Greek often denotes a personal relation between the knower and the known, so that the knowledge of an object implies the influence of that object upon the knower. So John 2:24, John 2:25; 1 Corinthians 2:8; 1 John 4:8. In John the relation itself is expressed by the verb. John 17:3, John 17:25; 1 John 5:20; 1 John 4:6; 1 John 2:3, 1 John 2:4, 1 John 2:5. [source]
2 Corinthians 5:14 The love of Christ []
Christ's love to men. See on 1 John 2:5. [source]
Galatians 5:22 Love [ἀγάπη]
Comp. love of the Spirit, Romans 15:30. In Class. φιλεῖν is the most general designation of love, denoting an inner inclination to persons or things, and standing opposed to μισεῖν or ἐχθαίρειν tohate. It occasionally acquires from the context a sensual flavor, as Hom. Od. xviii. 325; Hdt. iv. 176, thus running into the sense of ἐρᾶν which denotes sensual love. It is love to persons and things growing out of intercourse and amenities or attractive qualities. Στέργειν (not in N.T., lxx, Sirach 27:17) expresses a deep, quiet, appropriating, natural love, as distinguished from that which is called out by circumstances. Unlike φιλεῖν , it has a distinct moral significance, and is not applied to base inclinations opposed to a genuine manly nature. It is the word for love to parents, wife, children, king or country, as one's own. Aristotle (Nic. ix. 7,3) speaks of poets as loving ( στέργοντες ) their own poems as their children. See also Eurip. Med. 87. Ἁγαπᾶν is to love out of an intelligent estimate of the object of love. It answers to Lat. diligere, or Germ. schatzen to prize. It is not passionate and sensual as ἐρᾶν . It is not, like φιλεῖν , attachment to a person independently of his quality and created by close intercourse. It is less sentiment than consideration. While φιλεῖν contemplates the person, ἀγαπᾶν contemplates the attributes and character, and gives an account of its inclination. Ἁγαπᾶν is really the weaker expression for love, as that term is conventionally used. It is judicial rather than affectionate. Even in classical usage, however, the distinction between ἀγαπᾶν and φιλεῖν is often very subtle, and well-nigh impossible to express. In N.T. ἐπιθυμαῖν todesire or lust is used instead of ἐρᾶν . In lxx ἀγαπᾶν is far more common than φιλεῖν . Φιλεῖν occurs only 16 times in the sense of love, and 16 times in the sense of kiss; while ἀγαπᾶν is found nearly 300 times. It is used with a wide range, of the love of parent for child, of man for God, of God for man, of love to one's neighbor and to the stranger, of husband for wife, of love for God's house, and for mercy and truth; but also of the love of Samson for Delilah, of Hosea for his adulterous wife, of Amnon's love for Tamar, of Solomon's love for strange women, of loving a woman for her beauty. Also of loving vanity, unrighteousness, devouring words, cursing, death, silver. -DIVIDER-
-DIVIDER-
The noun ἀγάπη , oClass., was apparently created by the lxx, although it is found there only 19 times. It first comes into habitual use in Christian writings. In N.T. it is, practically, the only noun for love, although compound nouns expressing peculiar phases of love, as brotherly love, love of money, love of children, etc., are formed with φίλος , as φιλαδελφία, φιλαργυρία, φιλανθρωπία . Both verbs, φιλεῖν and ἀγαπᾶν occur, but ἀγαπᾶν more frequently. The attempt to carry out consistently the classical distinction between these two must be abandoned. Both are used of the love of parents and children, of the love of God for Christ, of Christ for men, of God for men, of men for Christ and of men for men. The love of man for God and of husband for wife, only ἀγαπᾶν . The distinction is rather between ἀγαπᾶν and ἐπιθυμεῖν than between ἀγαπᾶν and φιλεῖν . Love, in this passage, is that fruit of the Spirit which dominates all the others. See Galatians 5:13, Galatians 5:14. Comp. 1 Corinthians 13:1-13; 1 John 2:5, 1 John 2:9-11; 1 John 3:11, 1 John 3:14-16; 1 John 4:7-11, 1 John 4:16-21; 1 John 5:1-3. [source]

Galatians 1:16 To reveal his Son in me [ἀποκαλύψαι τὸν υἱὸν αὐτοῦ ἐν ἐμοὶ]
In N.T. ἀποκαλύπτειν toreveal is habitually used with the simple dative of the subject of the revelation, as Luke 10:21. Once with εἰς unto Romans 8:18: with ἐν inof the sphere in which the revelation takes place, only here, unless Romans 1:17be so explained; but there ἐν is probably instrumental. Render ἐν here by the simple in: in my spirit, according to the familiar N.T. idea of God revealing himself, living and working in man's inner personality. See, for instance, Romans 1:19; Romans 5:5; Romans 8:10, Romans 8:11; 1 Corinthians 3:16; 1 Corinthians 14:25; 2 Corinthians 4:6; 1 John 2:5, 1 John 2:14, etc. Lightfoot explains, to reveal his Son by or through me to others. But apart from the doubtful use of ἐν , this introduces prematurely the thought of Paul's influence in his subsequent ministry. He is speaking of the initial stages of his experience. [source]
1 Thessalonians 1:3 In our Lord, etc. [τοῦ κυρίου]
Lit. of our Lord. For a similar use of the genitive, see John 5:42; 1 John 2:5, 1 John 2:15; Acts 9:31; Romans 1:5; Romans 3:18, Romans 3:22, Romans 3:26, etc. Connect with hope only. [source]
1 John 4:8 Is love [ἀγάπη ἐστίν]
See on God is light (1 John 1:5), and the truth (1 John 1:6); also God is spirit (John 4:24). Spirit and light are expressions of God's essential nature. Love is the expression of His personality corresponding to His nature. See on love of God (1 John 2:5). Truth and love stand related to each other. Loving is the condition of knowing. [source]
1 John 2:3 Hereby [ἐν τούτῳ]
Lit., in this. Characteristic of John. See John 8:35; John 15:8; John 16:30; 1 John 2:5; 1 John 3:24; 1 John 4:13; 1 John 5:2; 1 John 3:16; 1 John 3:19; 1 John 4:2. The expression points to what follows, “if we keep His commandments,” yet with a covert reference to that idea as generally implied in the previous words concerning fellowship with God and walking in the light. [source]
1 John 2:15 The love of the Father [ἡ ἀγάπη τοῦ πατρὸς]
The phrase occurs only here in the New Testament. It means love towards the Father, yet as generated by the Father's love to man. Compare 1 John 3:1. See on love of God, 1 John 2:5. [source]
1 John 2:5 Is the love of God perfected [ἡ ἀγάπη τοῦ Θεοῦ τετελείωται]
Rev., rendering the perfect tense more closely, hath the love of God been perfected. The change in the form of this antithetic clause is striking. He who claims to know God, yet lives in disobedience, is a liar. We should expect as an offset to this: He that keepeth His commandments is of the truth; or, the truth is in him. Instead we have, “In him has the love of God been perfected.” In other words, the obedient child of God is characterized, not by any representative trait or quality of his own personality, but merely as the subject of the work of divine love: as the sphere in which that love accomplishes its perfect work. The phrase ἡ ἀγάπη τοῦ Θεοῦ the love of God, may mean either the love which God shows, or the love of which God is the object, or the love which is characteristic of God whether manifested by Himself or by His obedient child through His Spirit. John's usage is not decisive like Paul's, according to which the love of God habitually means the love which proceeds from and is manifested by God. The exact phrase, the love of God or the love of the Father, is found in 1 John 3:16; 1 John 4:9, in the undoubted sense of the love of God to men. The same sense is intended in 1 John 3:1, 1 John 3:9, 1 John 3:16, though differently expressed. The sense is doubtful in 1 John 2:5; 1 John 3:17; 1 John 4:12. Men's love to God is clearly meant in 1 John 2:15; 1 John 5:3. The phrase occurs only twice in the Gospels (Luke 6:42; John 5:42), and in both cases the sense is doubtful. Some, as Ebrard, combine the two, and explain the love of God as the mutual relation of love between God and men. It is not possible to settle the point decisively, but I incline to the view that the fundamental idea of the love of God as expounded by John is the love which God has made known and which answers to His nature. In favor of this is the general usage of ἀγάπη lovein the New Testament, with the subjective genitive. The object is more commonly expressed by εἰς towardsor to. See 1 Thessalonians 3:12; Colossians 1:4; 1 Peter 4:8. Still stronger is John's treatment of the subject in ch. 4. Here we have, 1 John 4:9, the manifestation of the love of God in us ( ἐν ἡμῖν ) By our life in Christ and our love to God we are a manifestation of God's love. Directly following this is a definition of the essential nature of love. “In this is love; i.e., herein consists love: not that we have loved God, but that He loved us ” (1 John 4:10). Our mutual love is a proof that God dwells in us. God dwelling in us, His love is perfected in us (1 John 4:12). The latter clause, it would seem, must be explained according to 1 John 4:10. Then (1 John 4:16), “We have known and believed the love that God hath in us ” (see on John 16:22, on the phrase have love ). “God is love;” that is His nature, and He imparts this nature to be the sphere in which His children dwell. “He that dwelleth in love dwelleth in God.” Finally, our love is engendered by His love to us. “We love Him because He first loved us” (1 John 4:19). -DIVIDER-
-DIVIDER-
In harmony with this is John 15:9. “As the Father loved me, I also loved you. Continue ye in my love.” My love must be explained by I loved you. This is the same idea of divine love as the sphere or element of renewed being; and this idea is placed, as in the passage we are considering, in direct connection with the keeping of the divine commandments. “If ye keep my commandments ye shall abide in my love.”-DIVIDER-
This interpretation does not exclude man's love to God. On the contrary, it includes it. The love which God has, is revealed as the love of God in the love of His children towards Him, no less than in His manifestations of love to them. The idea of divine love is thus complex. Love, in its very essence, is reciprocal. Its perfect ideal requires two parties. It is not enough to tell us, as a bare, abstract truth, that God is love. The truth must be rounded and filled out for us by the appreciable exertion of divine love upon an object, and by the response of the object. The love of God is perfected or completed by the perfect establishment of the relation of love between God and man. When man loves perfectly, his love is the love of God shed abroad in his heart. His love owes both its origin and its nature to the love of God. -DIVIDER-
-DIVIDER-
The word verily ( ἀληθῶς ) is never used by John as a mere formula of affirmation, but has the meaning of a qualitative adverb, expressing not merely the actual existence of a thing, but its existence in a manner most absolutely corresponding to ἀλήθεια truthCompare John 1:48; John 8:31. Hath been perfected. John is presenting the ideal of life in God. “This is the love of God that we keep His commandments.” Therefore whosoever keepeth God's word, His message in its entirety, realizes the perfect relation of love. [source]

1 John 2:3 Hereby [εν τουτωι]
See this phrase also in 1 John 2:5; 1 John 3:16, 1 John 3:19, 1 John 3:24; 1 John 4:2, 1 John 4:13; 1 John 5:2. That is explained by the εαν — ean clause, “if we keep his commandments” (εαν τηρωμεν — ean tērōmen condition of the third class, εαν — ean with present active subjunctive, “if we keep on keeping”), the clause itself in apposition with τουτωι — toutōi (locative case). [source]
1 John 2:15 If any man love [εαν τις αγαπαι]
Third-class condition with εαν — ean and present active subjunctive of αγαπαω — agapaō (same form as indicative), “if any keep on loving the world.”The love of the Father (η αγαπη του πατρος — hē agapē tou patros). Objective genitive, this phrase only here in N.T., with which compare “love of God” in 1 John 2:5. In antithesis to love of the world. [source]
1 John 2:15 The love of the Father [η αγαπη του πατρος]
Objective genitive, this phrase only here in N.T., with which compare “love of God” in 1 John 2:5. In antithesis to love of the world. [source]
1 John 4:9 Was manifested [επανερωτη]
First aorist passive indicative of πανεροω — phaneroō The Incarnation as in 1 John 3:5. Subjective genitive as in 1 John 2:5. [source]
1 John 4:12 If we love one another [εαν αγαπωμεν αλληλους]
Third-class condition with εαν — ean and the present active subjunctive, “if we keep on loving one another.”God abideth in us (ο τεος εν ημιν μενει — ho theos en hēmin menei). Else we cannot go on loving one another.His love More than merely subjective or objective (1 John 2:5; 1 John 4:9). “Mutual love is a sign of the indwelling of God in men” (Brooke).Is perfected (τετελειωμενη εστιν — teteleiōmenē estin). Periphrastic (see usual form τετελειωται — teteleiōtai in 1 John 2:5; 1 John 4:17) perfect passive indicative of τελειοω — teleioō (cf. 1 John 1:4). See 1 John 4:18 for “perfect love.” [source]
1 John 4:12 His love [η αγαπη αυτου]
More than merely subjective or objective (1 John 2:5; 1 John 4:9). “Mutual love is a sign of the indwelling of God in men” (Brooke).Is perfected (τετελειωμενη εστιν — teteleiōmenē estin). Periphrastic (see usual form τετελειωται — teteleiōtai in 1 John 2:5; 1 John 4:17) perfect passive indicative of τελειοω — teleioō (cf. 1 John 1:4). See 1 John 4:18 for “perfect love.” [source]
1 John 4:12 Is perfected [τετελειωμενη εστιν]
Periphrastic (see usual form τετελειωται — teteleiōtai in 1 John 2:5; 1 John 4:17) perfect passive indicative of τελειοω — teleioō (cf. 1 John 1:4). See 1 John 4:18 for “perfect love.” [source]
2 John 1:6 That we should walk [ινα περιπατωμεν]
Object clause in nominative case in apposition with αγαπη — agapē with ινα — hina and the present active subjunctive of περιπατεω — peripateō “that we keep on walking.”The commandment (η εντολη — hē entolē). The one just mentioned with the same construction with ινα — hina as in 1 John 3:23. John changes from the first person plural to the second (ηκουσατε — ēkousate as in 1 John 2:7, περιπατητε — peripatēte) as in 1 John 2:5, 1 John 2:7.In it Either to αλητειαι — alētheiāi (truth) of 2 John 1:4, αγαπη — agapē of this verse, or εντολη — entolē of this verse. Either makes good sense, probably “in love.” With περιπατεω — peripateō (walk) we have often εν — en (1 John 1:7; 1 John 2:11, etc.) or κατα — kata (according to) as in Mark 7:5; 1 Corinthians 3:3; 2 Corinthians 10:2, etc. [source]
2 John 1:6 The commandment [η εντολη]
The one just mentioned with the same construction with ινα — hina as in 1 John 3:23. John changes from the first person plural to the second (ηκουσατε — ēkousate as in 1 John 2:7, περιπατητε — peripatēte) as in 1 John 2:5, 1 John 2:7. [source]

What do the individual words in 1 John 2:5 mean?

Whoever however - may keep His - word truly in him the love - of God has been perfected By this we know that Him we are
ὃς δ’ ἂν τηρῇ αὐτοῦ τὸν λόγον ἀληθῶς ἐν τούτῳ ἀγάπη τοῦ Θεοῦ τετελείωται Ἐν τούτῳ γινώσκομεν ὅτι αὐτῷ ἐσμεν

ὃς  Whoever 
Parse: Personal / Relative Pronoun, Nominative Masculine Singular
Root: ὅς 
Sense: who, which, what, that.
δ’  however 
Parse: Conjunction
Root: δέ  
Sense: but, moreover, and, etc.
ἂν  - 
Parse: Particle
Root: ἄν  
Sense: has no exact English equivalent, see definitions under AV.
τηρῇ  may  keep 
Parse: Verb, Present Subjunctive Active, 3rd Person Singular
Root: τηρέω  
Sense: to attend to carefully, take care of.
αὐτοῦ  His 
Parse: Personal / Possessive Pronoun, Genitive Masculine 3rd Person Singular
Root: αὐτός  
Sense: himself, herself, themselves, itself.
τὸν  - 
Parse: Article, Accusative Masculine Singular
Root:  
Sense: this, that, these, etc.
λόγον  word 
Parse: Noun, Accusative Masculine Singular
Root: λόγος  
Sense: of speech.
ἀληθῶς  truly 
Parse: Adverb
Root: ἀληθῶς  
Sense: truly, of a truth, in reality, most certainly.
ἀγάπη  love 
Parse: Noun, Nominative Feminine Singular
Root: ἀγάπη  
Sense: brotherly love, affection, good will, love, benevolence.
τοῦ  - 
Parse: Article, Genitive Masculine Singular
Root:  
Sense: this, that, these, etc.
Θεοῦ  of  God 
Parse: Noun, Genitive Masculine Singular
Root: θεός  
Sense: a god or goddess, a general name of deities or divinities.
τετελείωται  has  been  perfected 
Parse: Verb, Perfect Indicative Middle or Passive, 3rd Person Singular
Root: τελειόω  
Sense: to make perfect, complete.
τούτῳ  this 
Parse: Demonstrative Pronoun, Dative Neuter Singular
Root: οὗτος  
Sense: this.
γινώσκομεν  we  know 
Parse: Verb, Present Indicative Active, 1st Person Plural
Root: γινώσκω  
Sense: to learn to know, come to know, get a knowledge of perceive, feel.
ὅτι  that 
Parse: Conjunction
Root: ὅτι  
Sense: that, because, since.
ἐσμεν  we  are 
Parse: Verb, Present Indicative Active, 1st Person Plural
Root: εἰμί  
Sense: to be, to exist, to happen, to be present.