5:1 Whosoever {1} believeth that Jesus is the {a} Christ is born of God: and every one that loveth him that begat loveth {b} him also that is begotten of him.

(1) He advances in the same argument, showing how both those loves come to us, from that love with which God loves us, that is, by Jesus our mediator laid hold on by faith, in whom we are made the children of God, and do love the Father from whom we are begotten, and also our brothers who are begotten with us.

(a) Is the true Messiah.

(b) By one, he means all the faithful.

5:2 {2} By this we know that we love the children of God, when we love God, and keep his {c} commandments.

(2) The love of our neighbour depends on the love with which we love God, that this last must go before the first: of which it follows, that that is not to be called love, when men agree together to do evil, neither that, when as in loving our neighbours, we do not respect God's commandments.

(c) There is no love where there is no true doctrine.

5:3 {3} For this is the love of God, that we keep his commandments: {4} and his commandments are not {d} grievous.

(3) The reason: to love God, is to keep his commandments, which being so, and seeing that both the loves are commanded by the same lawmaker, (as he taught before) it follows also, that we do not love our neighbours, when we break God's commandments.

(4) Because experience teaches us that there is no ability in our flesh, neither will to perform God's commandments, therefore lest the apostle should seem, by so often putting them in mind of the keeping of the commandments of God, to require things that are impossible, he pronounces that the commandments of God are not in any way grievous or burdensome, that we can be oppressed with the burden of them.

(d) To those who are regenerate, that is to say, born again, who are led by the Spirit of God, and are through grace delivered from the curse of the law.

5:4 {5} For whatsoever is born of God overcometh the world: {6} and this is the victory that {e} overcometh the world, [even] our {f} faith.

(5) A reason: Because by regeneration we have received strength to overcome the world, that is to say, whatever strives against the commandments of God.

(6) He declares what that strength is, that is, faith.

(e) He uses the time that is past, to give us to understand, that although we are in the battle, yet undoubtedly we shall be conquerors, and are most certain of the victory.

(f) Which is the instrumental cause, and as a means and hand by which we lay hold on him, who indeed performs this, that is, has and does overcome the world, even Christ Jesus.

5:5 {7} Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?

(7) Moreover he declares two things, the one, what true faith is, that is, that which rests on Jesus Christ the Son of God alone: on which follows the other, that is, that this strength is not proper to faith, but by faith as an instrument is drawn from Jesus Christ the Son of God.

5:6 {8} This is he that came by water and blood, [even] Jesus Christ; {9} not by water only, but by water and blood. And it is the {g} Spirit that beareth witness, because the Spirit is truth.

(8) He proves the excellency of Christ, in whom only all things are given us by six witnesses, three heavenly, and three earthly, who wholly and completely agree together. The heavenly witnesses are, the Father who sent the Son, the Word itself, which became flesh, and the Holy Spirit. The earthly witnesses are water, (that is our sanctification) blood, (that is, our justification) the Spirit, (that is, acknowledging of God the Father in Christ by faith) through the testimony of the Holy Spirit.

(9) He warns us not to separate water from blood (that is sanctification from justification, or righteousness, begun from righteousness imputed) for we do not stand on sanctification, but so far as it is a witness of Christ's righteousness imputed to us: and although this imputation of Christ's righteousness is never separated from sanctification, yet it is the only matter of our salvation.

(g) Our spirit which is the third witness, testifies that the holy Sprit is truth, that is to say, that that is true which he tells us, that is, that we are the sons of God.

5:7 For there are three that bear record in heaven, the Father, the {h} Word, and the Holy Ghost: and these three are {i} one.

(h) See Joh 8:13,14

(i) Agree in one.

5:9 {10} If we receive the witness of men, the witness of God is greater: for {k} this is the witness of God which he hath testified of his Son.

(10) He shows by an argument of comparison, of what great weight the heavenly testimony is, that the Father has given of the Son, to whom agrees both the Son himself and the Holy Spirit.

(k) I conclude correctly: for the testimony which I said is given in heaven, comes from God, who sets forth his Son.

5:10 {11} He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.

(11) He proves the sureness of the earthly witness by every man's conscience having that testimony in itself, whose conscience he says cannot be deceived because it agrees with the heavenly testimony which the Father gives of the Son: for otherwise the Father must be a liar, if the conscience which agrees and assents to the Father, should lie.

5:11 {12} And this is the record, that God hath given to us eternal life, and this life is in his Son.

(12) Now at length he shows what this testimony is that is confirmed with so many witnesses: that is, that life or everlasting happiness is the gift of God, which is the Son, and proceeds from him to us, who by faith are joined with him, so that without him, life is nowhere to be found.

5:13 {13} These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.

(13) The conclusion of the epistle, in which he shows first of all, that even they who already believe, need this doctrine, that they may grow more and more in faith: that is to say, that they may be daily more and more certain of their salvation in Christ, through faith.

5:14 {14} And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us:

(14) Because we do not yet in effect obtain that which we hope for, the apostle combines invocation or prayer with faith, which he will have proceed from faith, and moreover to be conceived in such a way, that nothing is asked but that which is agreeable to the will of God: and such prayers cannot be useless.

5:16 {15} If any man see his brother sin a sin [which is] not unto death, {l} he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.

(15) We have to make prayers not only for ourselves, but also for our brothers who sin, that their sins be not to death: and yet he excepts that sin which is never forgiven, or the sin against the Holy Spirit, that is to say, a universal and wilful falling away from the known truth of the gospel.

(l) This is as if he said, let him ask the Lord to forgive him, and he will forgive him being so asked.

5:17 {16} All unrighteousness is sin: and there is a sin not unto death.

(16) The taking away of an objection: indeed all iniquity is comprehended under the name of sin: but yet we must not despair therefore, because every sin is not deadly, and without hope of remedy.

5:18 {17} We know that whosoever is born of God sinneth not; but he that is begotten of God keepeth himself, and that wicked one toucheth him not.

(17) A reason why not all, or rather why no sin is mortal to some: that is, because they are born of God, that is to say, made the sons of God in Christ, and being ended with his Spirit, they do not serve sin, nor are they mortally wounded by Satan.

5:19 {18} [And] we know that we are of God, and the whole world lieth in wickedness.

(18) Every man must particularly apply to himself the general promises, that we may certainly persuade ourselves, that whereas all the world is by nature lost, we are freely made the sons of God, by the sending of Jesus Christ his son to us, of whom we are enlightened with the knowledge of the true God and everlasting life.

5:20 And we know that the Son of God is come, and hath given us an understanding, that we may know him that is true, and we are in him that is true, [even] in his Son Jesus Christ. This is the true {m} God, and eternal life.

(m) The divinity of Christ is most clearly proved by this passage.

5:21 {19} Little children, keep yourselves from idols. Amen.

(19) He expresses a plain precept of taking heed of idols: which he contrasts with the only true God, that with this seal he might seal up all the former doctrine.