Verse by Verse

¹⁸ We know that whoever is born of God does not sin; but he who has been born of God keeps himself, and the wicked one does not touch him.

¹⁹ We know that we are of God, and the whole world lies under the sway of the wicked one.

²⁰ And we know that the Son of God has come and has given us an understanding, that we may know Him who is true; and we are in Him who is true, in His Son Jesus Christ. This is the true God and eternal life.

²¹ Little children, keep yourselves from idols. Amen.

Verses 19-21 form a summary of the whole Epistle. The believer possesses a divine nature, the object of his heart is Christ, and all outside of Him is idolatry. — Williams, page 1017.

know (v.18, 19, 20) — expresses the confidence we can have by faith

is born (v.18) — More lit., “whosoever has been [born],” expressive of the abiding effect of the Divine operations in the case of the believer. — Vine, page 107.

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does not sin (v.18) — This is in the present continuous tense. … The Apostle is not now speaking of sin unto death, but, as in chapter 3, of a continuous course of sin, which is entirely incompatible with the new birth. — Vine, page 107.

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Whereas the perfect tense, “he that hath been begotten,” refers to the believer as a child of God, in contrast to those who have not become so, the aorist or point tense “was begotten,” points to a fact in the past and refers to the Son of God, “the Only-Begotten from the Father” (John 1:14), in contrast to the evil one. Christ is the Keeper (cp. John 17:12). The rendering “him” (not “himself:) is supported by weighty manuscript evidence and is in keeping with the context. — Vine, page 107.

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touch (v.18) — “lay hold of” The evil one assaults, but he cannot sever the vital connection between the believer and Christ. — Vine, pages 107-108.

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While believers are beyond the power of the evil one to separate them from Christ, the rest of mankind, who constitute “the world” (v.19), are in his power (see John 12:31; 14:30; 16:11); they are controlled by him as “the prince of this world,” and their condition therefore that of spiritual death. — Vine, page 108.

an understanding (v.20) = forming a conclusion from certain facts

that we may know Him (v.20) — tense indicates a continuous process of getting to know God

Him who is true (v.20) — true as opposed to what is spurious and unreal, not true as opposed to what is false. … Again, God is not only the source of truth, He is the one and only genuine God. — Vine, page 109.

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Jesus Christ as the Son of God is identified as eternal life and also as the true God, one of the most striking examples of His full deity and oneness with the Father. — Grace, page 2226.

keep (v.21) = guard, a command to be constantly kept

¹⁴ Now this is the confidence that we have in Him, that if we ask anything according to His will, He hears us.

¹⁵ And if we know that He hears us, whatever we ask, we know that we have the petitions that we have asked of Him.

¹⁶ If anyone sees his brother sinning a sin which does not lead to death, he will ask, and He will give him life for those who commit sin not leading to death. There is sin leading to death. I do not say that he should pray about that.

¹⁷ All unrighteousness is sin, and there is sin not leading to death.

This is not a prayer promise for the Body of Christ and has led to much disappointment and disillusionment (Matthew 21:22; Mark 11:24; John 15:7; 16:23-24; 1 John 3:21-22). (For instruction in prayer for the Dispensation of Grace, see Romans 8:26-27; 15:30-33; Ephesians 1:15-23; 3:14-21; Philippians 1:9-11; 4:6-7; 4:19; Colossians 1:9-12). — Grace, page 2225.

brother (v.16) — another believer

This statement (v.15) presupposes that the condition mentioned in v.14 is fulfilled. In other words, on the ground that [the person’s] union with Christ gives [him] boldness towards God, and that [his] will is subject to His will, [he] will have the assurance that the petitions presented in the spirit of unselfishness and submission, have already been granted. — Vine, page 104.

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John does not elaborate [about the “sin unto death”], and comparing Scripture with Scripture does not give us complete surety as the term appears only here. The Law of Moses commanded the punishment of physical death for murder and other serious crimes (Acts 5:1-11). John also spoke of spiritual death earlier in this letter (1 John 3:14). Jesus warned the Jews of the blasphemy against the Holy Spirit, a sin that would never be forgiven (Matthew 12:31-32). In the Book of Revelation, John spoke of the sin of receiving the mark of the beast (Revelation 13:16-17; 14:9-11; 16:2; 19:20; 20:4). Actually, these are all related sins of unbelief and will culminate in worshipping the Beast and his image (Revelation 13:1-18). They refer back to a prior dispensation but also to the future Tribulation period. None of these sins are unforgivable in the present dispensation. Paul assured believing Gentiles under grace that all sin has been forgiven and will not be counted against us (Acts 13:38-39; Colossians 2:13; Romans 4:6-8). — Grace, page 2225.

⁹ If we receive the witness of men, the witness of God is greater; for this is the witness of God which He has testified of His Son.

¹⁰ He who believes in the Son of God has the witness in himself; he who does not believe God has made Him a liar, because he has not believed the testimony that God has given of His Son.

¹¹ And this is the testimony: that God has given us eternal life, and this life is in His Son.

¹² He who has the Son has life; he who does not have the Son of God does not have life.

¹³ These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God.

If (v.9) — The “If” simply introduces what is an acknowledged fact, not a matter of doubt. That is to say “if we receive the witness of men, and it is an acknowledged fact that we do …” — Vine, page 99.

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receive (v.9) = accept as valid. If we are accustomed to accept a testimony in regard to earthly facts, how much more shall we rely confidently upon the Divine testimony! — Vine, page 99.

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this is the witness (v.9) — The statement lays stress on the fact that the witness is not merely concerning a Person named Jesus, but that it is a witness concerning Him as the Son of God. The perfect tense “hath born witness” expresses the abiding effects of the witness given. — Vine, page 99.

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He who believes (v.10) — [the original] combines the thoughts of the direction in which faith is exercised and the rest it reposes on its object. Faith thus exercised involves the fullest trust in, and reliance upon, a person. — Vine, page 100,

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made Him a liar (v.10) — Since the witness concerning His Son has been given by God, not to accept it is to impute falsehood to Him. — Vine, page 100.

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There are four points to be noticed here particularly; firstly, the witness comes from God; secondly, it is concerning His Son and His mission, His death and resurrection; thirdly, the witness is three-fold, that of the Spirit, the water and the blood; fourthly, it is a witness concerning the life in Christ as His Son. Such a witness commands our faith, which therefore rests upon an absolutely reliable basis. Accordingly, faith is the effect of the witness, and is spoken of as the habitual attitude of the soul. Again, the witness is an abiding possession which glorifies God. In contrast with this, the unbeliever, who deliberately refuses the testimony that God has given, makes Him a liar. — Vine, pages 100-101.

testimony (vs.10-11) = witness

Summing up his subject (v.11), [John] shows how the possession of eternal life involves the possession of the Son of God Himself, without whom eternal life is impossible. — Vine, page 101.

has given (v.11) — tense emphasizes the greatness of the act

In the first part [of v.12], the words “the life” bear stress (i.e., it is the possession of life that is involved in the possession of the Son); in the last statement of the verse, the word “have” bears stress (he is destitute of life who has not the Son). — Vine, page 102.

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The Apostle … expresses the purpose of his Epistle (v.13), namely to confirm his readers in the assurance of their possession. — Vine, page 102.

These things (v.13) — the entire letter

The name of the Son of God (v.13) refers to who He is, i.e., the Christ, the Son of the living God (Matthew 16:16; John 11:27), and this is the message that the hearers of the Gospel of the Kingdom were to believe for salvation. — Grace, page 2225.

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While Paul’s revelation of the Gospel of Grace confirms the identity of Christ, the Son of God (Romans 1:3-4), that alone is not the complete saving message for the present-day Church. Paul makes clear that it is also faith in His redemptive work on the cross (Romans 3:20-28; 1 Corinthians 1:18-2:2). While His cross work is mentioned in the non-Pauline writings (1 Peter 1:18-19; 2:24; 3:18; 1 John 2:2; 4:10; Revelation 1:5), it was not required as a necessary object of faith for kingdom believers for salvation. — Grace, page 2225.

⁶ This is He who came by water and blood—Jesus Christ; not only by water, but by water and blood. And it is the Spirit who bears witness, because the Spirit is truth.

⁷ For there are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one.

⁸ And there are three that bear witness on earth: the Spirit, the water, and the blood; and these three agree as one.

The threefold witness is about to be given (v.8), but, as a preliminary to this, the Person of the Holy Spirit is mentioned first alone (v.6), as being in the Godhead. The Spirit of God bears witness by His operation in the heart concerning the Person and Work of Christ. On the day of Pentecost and subsequently He bore witness through the Apostles and others. He bears witness through the Holy Scriptures, which are God-breathed (2 Timothy 3:16), and through testimony in accordance with them the Scriptures constitute the truth because “The Spirit is the truth.”

The Apostle conveys through this latter statement the Deity of the Holy Spirit. “God is true” (Psalm 31:5). Christ is “the truth” (John 14:6), and “the Spirit is the truth (John 14:16).” He is one in Divine nature with the Father and the Son.

The special witness to which this passage refers is the identity of Jesus with the Son of God, and to this great fact the Spirit of truth bears witness. — Vine, page 98.

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John gives three witnesses that Jesus is God (v.6); (1) Water — His baptism (Matthew 3:13-17; John 1:32-34); (2) Blood — His sacrificial blood (Hebrews 9:12-15); and (3) the Spirit — the Holy Spirit’s witness through the Word (1 John 3:24; 4:13). — Grace, page 2225.

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The seventh verse … is not part of the original. No Greek manuscript earlier than the 14th century contains the passage. No version earlier than the 5th century in any other language contains it. … Moreover, the statement makes a break into the sense of the whole passage. — Vine, page 98.

There are three (v.8) — present tense indicates continuing action.

the Spirit, the water, and the blood (v.8) — The triple witness is a witness concerning life (see v.11, which is to be connected immediately with this verse). The Spirit of God applies to the believer’s heart the realization of the efficacy of the blood of Christ and the ministry of what is set forth by the water. — Vine, page 99.

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The reason the testimony of water was so weighty is because it was a requirement for obedient Jews (Mark 1:4-5). — Grace, page 2225.

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these three agree as one (v.8) — They are united in one witness and have one object and effect. For the point of the witness and its effects, see vs.11-12.

1 Whoever believes that Jesus is the Christ is born of God, and everyone who loves Him who begot also loves him who is begotten of Him.

² By this we know that we love the children of God, when we love God and keep His commandments.

³ For this is the love of God, that we keep His commandments. And His commandments are not burdensome.

⁴ For whatever is born of God overcomes the world. And this is the victory that has overcome the world—our faith.

⁵ Who is he who overcomes the world, but he who believes that Jesus is the Son of God?

whoever (v.1) = lit. “everyone that believes,” “every  believer”

is born of God (v.1) = “has been born”

Since every believer has part in the gift of Divine life, by which he is born of God, it is inevitable that this life will be manifested in love to those who likewise are born of God (v.1) … The whole of this passage teaches, not that in loving our brother we rise to the love of God, but that, on the contrary, God Himself is the source of all the love that we can and do show.— Vine, page 93.

By this we know (v.2) = lit. “By this we have the constant experience of knowing”

In [1 John 4:20-21] love to God is the fulfilment of His commandments, which are shown to have their evidence in the love of His children. This same truth is stressed by being put in the converse way in the present passage (v.2). In other words, if we want to know whether we love our brother, it is necessary to ask if we love God, for the motive cause of love lies in God Himself, for “God is love.” Here the test of our love to God is the doing of His commandments, that is to say, in loving our neighbor. Taken together, then, the two passages show that love to God and love to one another are essentially associated and mutually evidential. — Vine, page 94.

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commandments (v.3) — [God’s] commandments make known His nature, and we show His nature when we keep them. — Vine, page 94.

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burdensome (v.3) — The statement does not mean this, that God’s commandments are not difficult to keep, it means that they do not impose a burden when they are kept (Psalm 19:11; Matthew 11:30). … the Lord supplies strength for the fulfilment of His commandments, His love makes them light, and He rewards the doing of it. — Vine, pages 94-95.

Yet again, remember John was writing to believers of the kingdom gospel who had/will have the law written on their hearts. So, to hate a brother proved that the Spirit hadn’t written the law on their hearts, which, in turn, proved that they didn’t believe in Jesus Christ. Or to put it another way:

A genuine begotten one will love a fellow begotten one because of the work of the Spirit. Why then the command to love (1 John 4:21). Because, for the kingdom believer, the command to love works in harmony with the Spirit of God and their will, to cause them to obey God’s Word. The command to love will also reveal the hearts of the people making a profession of knowing God. For the believer, loving each other will reveal that they have the Spirit of God and are born of God; for the false professor the lack of love (or hating their brother) will prove that they lack eternal life. — Grace, page 2224.

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The spirit of the world is opposed to the fulfilment of the commandments of God. To do His commandments, therefore, is to overcome (v.4) the spirit of the world. — Vine, page 95.

overcome (v.4) = conquer, defeat, prevail

Faith (v.4) not merely brings to us the new birth, but with it the power to overcome the opposition of the spirit that characterizes the world. The victory which was thus gained by faith, the proving of things not seen, brought us into a life which was designed to be characterized by victorious power. — Vine, page 95.

²⁰ If someone says, “I love God,” and hates his brother, he is a liar; for he who does not love his brother whom he has seen, how can he love God whom he has not seen?

²¹ And this commandment we have from Him: that he who loves God must love his brother also.

If someone says (v.20) — See 1 John 1:6, 8, 10; 2:4, 6, 9, etc. It is plainly characteristic of this Epistle, and is indicative of the many evil conditions and influences which were at work, to the detriment of the spiritual life of believers. Against this mere professionalism they were to be on their guard, and particularly the profession here mentioned, of showing love to God while denying it to our brother. If we refrain from showing love to our brother, however much we may know of the doctrine of love to God, there is no real comprehension or appreciation of it, because there is no response on our part to His love (v.19). … Such a person is a liar, and his character bears no resemblance to that of God. He neither knows the nature of God, nor does he enjoy communion with Him (v.16). He does not know God (v.8) nor has he been born of Him (v.7). His spirit is not the Spirit of truth but the spirit of error (v.6). — Vine, pages 88-89.

Again, it is very important to remember that John was writing to those saved under the kingdom gospel who had the law of God written on their hearts. We should also love others as a response to God’s love for us, but in the age of grace, this love is not a requirement for, or evidence of, salvation.

has seen (v.20) — The perfect tense expresses an abiding condition. The brother is viewed not as one simply whom we can see but as one who is constantly before our eyes. — Vine, page 89.

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how can he love (v.20) — It is not simply that what is invisible is more difficult to love than what is visible, but that the absence of practical love to one’s brother in the material circumstances of every-day life rules out the possibility of love to God; that is essentially a matter of faith, as being exercised towards Him who is invisible. There is a connection between this verse and what is said of the invisibility of God in v.12. — Vine, page 89.

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[In v.21] what has been regarded as spiritually inevitable in the preceding verse, is put as a distinct command. Not only is love to God impossible where we do not love our brother, but love to our brother is binding upon us. — Vine, page 89.

¹⁷ Love has been perfected among us in this: that we may have boldness in the day of judgment; because as He is, so are we in this world.

¹⁸ There is no fear in love; but perfect love casts out fear, because fear involves torment. But he who fears has not been made perfect in love.

¹⁹ We love Him because He first loved us.

The opening statement of verse 17 may be rendered as follows: “In this is love (i.e., the Divine love) perfected in us.” The “herein” connects the preceding verse with what follows. When God sees the perfecting of His love in us, as shown in our love to others, that is to say, when He sees us united to Him, not only positionally but in practical experience, He sees in us the likeness of His own Son, the One in whom He is well pleased; and in this way “as He is, even so are we in this world.” This last statement has to do with the character of Christ, not with the fact that we are saved because of our identification with Christ. — Vine, page 87.

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boldness (v.17) — Compare with 1 John 3:19-21. John’s thought is that the working of God’s perfect love in us does away with fear of God’s judgment at His appearing, so giving confidence and boldness in that day (Matthew 25:31-46; 1 John 2:28). The last part of v.17 shows the holy standing or position of the believer in Christ. — Grace, page 2224.

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This (v.18) gives a proof, by way of a general statement of fact, of what was stated in the preceding verse as to our having boldness in the Day of Judgment because love is made perfect in us. In other words, that must be so because of the impossibility of the co-existence of love and fear in the way here mentioned. Fear is expelled by perfect love, and love is prevented by fear from being perfected. … The point is that, where God’s love is being perfected in us, it gives no room for fear; not, again, the fear of God in which we are to walk, a fear lest we should grieve Him, but the fear of meeting with His reprobation. — Vine, page 88.

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fears (v.18) — The present participle expresses a habitual state, the state which is the negation of the enjoyment of love; love which is the fulfilling of the Law (Romans 13:10) leaves nothing to be feared. — Vine, page 88.

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The “Him” … is not in the most authentic manuscripts. It was introduced as a result of a misapprehension. The Apostle is not here speaking of our showing love to God in response to His love to us; his point is that no exercise of Christian love on our part is possible apart from God’s love to us. — Vine, page 88.

¹² No one has seen God at any time. If we love one another, God abides in us, and His love has been perfected in us.

¹³ By this we know that we abide in Him, and He in us, because He has given us of His Spirit.

¹⁴ And we have seen and testify that the Father has sent the Son as Savior of the world.

¹⁵ Whoever confesses that Jesus is the Son of God, God abides in him, and he in God.

¹⁶ And we have known and believed the love that God has for us. God is love, and he who abides in love abides in God, and God in him.

No one has seen God (v.12) — This is not quite the same statement as in John 1:18. … [There] the word is simply “to see,” and the declaration there is that God is invisible. Here, however, the verb implies contemplation, something of more comprehensive character than merely seeing. In both statements the stress is on the word “God,” which in each case stands first in the sentence in the original. — Vine, page 82-83.

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The connection with the preceding statement (v.12) seems to somewhat as follows: “While for anyone to behold God is an impossibility, and His presence is not discernible by contemplation, yet we may have the definite experience of His very presence, and this experience is made good in our case if we love on another. Moreover, His presence is not simply external, for He abides in us. He is not simply existent but resident. More still, since God is love, it follows that if we love one another, as is enjoined in His Word, His love has been perfected in us.” — Vine, page 83.

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His love (v.12) — is not simply our love to Him, nor again is it simply His love to man; the meaning seems to be that the love which characterizes Him (v.8), and has been manifested by Him (v.9), finds its expression and counterpart in the love which we exercise, and thus His love is perfected; that is to say, it reaches its fulfillment, in us. That this is the meaning is confirmed by verses 16 and 17 below. — Vine, page 83.

know (v.13) = know by continuous experience — both that we abide in Him and He abides in us

we (v.14) — John and the other apostles

has sent (v.14) — tense indicates a past event with continuing results

The connection [of verse 14 with the first 12 verses] is somewhat as follows: “While no man hath beheld God at any time, yet the Apostles had seen the Son of God, whom the Father had sent to be the Savior of the world, and who, being the Son of the Father, combined manhood with Deity, and is the great expression of God’s love. As, then, God has manifest His love in Christ, we are to show the same nature, the spirit of love, and this is possible only because the Holy Spirit, who proceeds from the Father, dwells in us. By this means God still reveals Himself through us. The Apostles, in companying with the Son of God in the days of His flesh, and subsequently to His resurrection, had themselves received personal evidence of this. To it they were bearing witness. Accordingly, through their testimony we are to continue to bear the same witness.” — Vine, page 84.

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There is a connection (v.15) with verse 2. The confession referred to there was in respect of the real humanity of Christ; here it has to do with His Divine Sonship. … In each place the confession is shown to be produced by the Holy Spirit, and here it involves the same spirit of love as was manifested by Christ, and a life that bears testimony to His saving power. … The tense of the verb rendered “confesses” conveys that thought not so much of time, as of decisiveness in the confession. — Vine, page 85.

we (v.16) — stressed, refers to all believers, those who have confessed that Jesus is the Son of God

That God is love (v.16) expresses His nature as made known to us in Christ. … Only by abiding in the love of God can true union with Him be realized. … The sending of His Son is a proof of God’s love, and the out-working of that love in us, in the exercise of love one to another, constitutes the great sign of the abiding presence of God within us and of our abiding in Him. — Vine, page 86.

⁷ Beloved, let us love one another, for love is of God; and everyone who loves is born of God and knows God.

⁸ He who does not love does not know God, for God is love.

⁹ In this the love of God was manifested toward us, that God has sent His only begotten Son into the world, that we might live through Him.

¹⁰ In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins.

¹¹ Beloved, if God so loved us, we also ought to love one another.

Love proceeds from God. The antichristian spirit is selfish. In the first of the three parts of the Epistle which deal with brother love, this was shown to be the characteristic, as well as the effect, of walking in the light (2:7-11). Secondly, it was set for as a characteristic of God’s children and a mark of their righteous conduct (3:10-18). Here it is shown to proceed from God as being essentially His attribute, and as having been manifested by Him in Christ. — Vine, page 79.

born of God (v.7) — born again by faith in Christ, as in 2:29 and 3:9.

everyone who loves is born of God (v.7) — Since love has God as its source, those who show the love that is here spoken of give evidence thereby that they are the children of God. Their spiritual life is derived from Him. … To exhibit Divine love is an evidence of more than the existence of the Divine relationship; it is a proof of the experience of a constant increase in the knowledge of God. — Vine, page 80.

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God is love (v.8) — This is a deeper truth than what was expressed at the beginning of verse 7. That predicated what the source of love was; this predicates the nature of God Himself. It does not convey, however, that God is simply loving and benevolent, nor that His love is merely a quality which He possesses; it is His essential nature, and it is for this special reason that one who does not exercise love has not been born of God and does not know Him. — Vine, page 80.

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God’s love is much more than an emotion, attested to by the fact that believers are empowered by the Holy Spirit to love even their enemies. It is an act of the will in obedience to God that treats another with the same spirit of self-sacrifice that Jesus Christ showed to you in His redemptive work on the cross. — Grace, page 2223.

In this (v.9) — in what follows

manifested (v.9) = openly shown

has sent (vs.9 and 10) — the tense emphasizes the continuing results

only begotten (v.9) — The title “only begotten” speaks of the eternal relationship of the Son to the Father, and at the same time expresses the Father’s delight in the Son. — Vine, page 81.

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that we might live through Him (v.9) — This, in addition to the fact just mentioned regarding the Person sent, is what makes the love of God unique. But for this act of infinite mercy we should have remained in spiritual darkness and have been consigned to the second death. To such a doom the word “live” is set in contrast, but it carries with it also all that is comprehended in the life imparted, namely, the qualities and activities which are involved therein and are manifested, for instance, by the exercise of love one to another. — Vine, page 81.

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The absolute spontaneity of the love of God is seen not only in the fact that God is love (v.8), that is so indeed, but in this also (v.10), that there was no quality in man to elicit that love; on the contrary, there was an absence in the human heart of that which was due to God. Whatever love there is in  us by reason of the new life imparted, is the outcome of, and a response, to His love. — Vine, page 82

sent (v.10) — tense indicates a historical fact

propitiation (v.10) = fully satisfying sacrifice

sent His Son to be the propitiation for our sins (v.10) — The Apostle takes us bac to what is antecedent to the gift of life. As he showed in chapter 1, the sin question must be settled before life is bestowed. In sending His only-begotten Son that we might live through Hi, the design was that he might first be the propitiation for our sins. — Vine, page 82.

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If God so love us (v.11) — The stress of the sentence is on the word “so,” as seen in the order in the original, “if so God loved us.” The “if” is not merely supposition, it is virtually equivalent to “since.” — Vine, page 82.

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We also ought to love one another (v.11) — This presents the practical conclusion from the double statement of the reason why God sent His Son, and resumes the exhortation in verse 7. What was there given as an exhortation, is here presented as an obligation, a debt. The order “we also” should be noted. The “also” is to be attached to the “we.” That is to say, “we, as well as God.” In other words, we should be “like God,” to manifest His nature and follow His example. This obligation rests, then, on the great foundation truth of the Atonement. — Vine, page 82.

⁴ You are of God, little children, and have overcome them, because He who is in you is greater than he who is in the world.

⁵ They are of the world. Therefore they speak as of the world, and the world hears them.

⁶ We are of God. He who knows God hears us; he who is not of God does not hear us. By this we know the spirit of truth and the spirit of error.

you (v.4) — emphasized, in contrast to the false prophets. You, who are “of God.”

little children (v.4) — Children of God by faith in Christ

overcome (v.4) — refused to listen to or be influenced by. Christ has overcome the world (John 16:33), and believers are “in Christ.”

them (v.4) — the false prophets, the antichrists of verses 1 and 3.

He that is in you (v.4) — The power for victory lies, not in the child of God himself, but in the One who indwells him. The realization of this gives triumphant confidence in face of spiritual foes, confidence, not in self, but in God. See Zechariah 4:6; 1 Corinthians 15:57; Ephesians 6:10. “He that is in you” is the Holy Spirit; “he that is in the world” is the evil one, “the prince of this world” (John 12:31), “the god of this world” (2 Corinthians 4:4). — Vine, page 77.

they (v.5) — the false prophets, the antichrists. The word is emphasized.

they speak as of the world (v.5) — The character of their teachings is consistent with their evil origins, and what they teach meets with read reception on the part of those who belong to the same system. … There is stress upon the phrase “of the world”; the order in the original is “therefore of the world they speak.” The meaning is not that they speak concerning, or about, the world, but that the world is the element which characterizes their utterances. The same spirit energizes both teachers and hearers. — Vine, pages 77-78.

We (v.6, first usage) — the apostles

We are of God (v.6) — This is set in contrast with the statement in verse 5. … As, then, the one antichristian spirit energizes the false prophets and their words (v.5), so, on the contrary, the Holy Spirit energizes both the teachers of the truth and the children of God who are taught by them. — Vine, page 78

we (v.6, second usage) — emphasized

he who knows God (v.6) — lit. “he who habitually is getting to know God.”

The Apostle’s statement (v.6) plainly reveals his consciousness of the Divine authority imparted to him and to his fellow-apostles. It also implies the Divine inspiration of their writings. — Vine, page 78.

by this (v.6) — what he has just written

the spirit of truth, and the spirit of error (v.6) — The Spirit of truth is the Holy Spirit, as in John 14:17; 15:26; 16:13. … The phrase “the Spirit of truth” may describe either: (1) the source from whence He has proceeded, as sent from the Father (John 14:26) and from the Son (John 16:7), or (2) His character as the One who is truth, or (3) The One who communicates the truth (John 16:13-14); (2) and (3) are closely associated and together seem to convey what is intended. The spirit of error or of deceit, a phrase found [only here] in the New Testament is the spirit which is characterized by, and communicates error, which comes from him of whom the Lord said that “he is a liar and the father thereof” (John 8:44). … Those who are children of God learn to know the Spirit of truth and the spirit of error, according to the way in which any teaching conforms, or otherwise, to the teaching of the Apostles [for us today, Paul, the apostle to the Gentiles]. — Vine, pages 78-79.

Again, John was writing to Jewish kingdom believers who had/will have the law written on their hearts. He allowed no wiggle room for half-hearted, divided, unloving, carnally minded believers like those grace believers Paul addressed in 1 Corinthians 1:11; 3:1-4; 5:1-13; 6:1-8; and 2 Corinthians 12:20-21.