The Geneva Bible Translation Notes, [1599], at sacred-texts.com
(1) Taking occasion by the name of the Spirit, lest love and charity should be separated from the worship of God, which chiefly depends on his true knowledge, he returns to that which he spoke of in the second chapter concerning the taking heed of antichrists: He will have us here take heed of two things, the one is, that seeing there are many false prophets, we should not trust every man: the other is, that because many men teach false things, we should not therefore believe any. We must then observe, that we may be able to discern the spirits of God which are to be followed, from impure spirits which are to be avoided.
(a) This is spoken by metonymy and it is as if he had said, Believe not every one who says that he has a gift of the Holy Spirit to do the office of a prophet.
(2) Hereby know ye the Spirit of God: (b) Every spirit that confesseth that (c) Jesus Christ is come in the (d) flesh is of God:
(2) He gives a certain and perpetual rule to know the doctrine of antichrist, that is, if either the divine or human nature of Christ, or the true uniting of them together is denied: or if the least jot that may be, be detracted from his office who is our only king, prophet and everlasting high priest.
(b) He speaks simply of the doctrine, and not of the person.
(c) The true Messiah.
(d) Is true man.
(3) Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world.
(3) He comforts the elect with a most sure hope of victory: but yet so, that he teaches them that they fight not with their own power, but with the virtue and power of God.
(4) They are of the world: therefore speak they of the world, and the world heareth them.
(4) He brings a reason why the world receives these teachers more willingly than the true: that is, because they speak nothing but that which is worldly: which is another note also to know the doctrine of antichrist by.
(5) We are of God: he that knoweth God heareth us; he that is not of God heareth not us. Hereby know we the (e) spirit of truth, and the spirit of error.
(5) He testifies to them that his doctrine and the doctrine of his companions, is the assured word of God which of necessity we have boldly to set against all the mouths of the whole world, and thereby discern the truth from falsehood.
(e) True prophets, against whom are false prophets, that is, those who err and lead others into error.
(6) Beloved, let us love one another: (7) for love is of God; and every one that loveth is born of God, and knoweth God.
(6) He returns to the commending of brotherly love and charity. (7) The first reason: because it is a very divine thing, and therefore very fitting for the sons of God: so that whoever is missing it cannot be said to know God correctly.
He that loveth not knoweth not God; (8) for God is love.
(8) A confirmation: for it is the nature of God to love men, of which we have a most manifest proof above all other, in that of his only free and infinite good will towards us his enemies, he delivered to death, not a common man, but his own Son, indeed his only begotten Son, to the end that we being reconciled through his blood might be partakers in his everlasting glory.
(9) Beloved, if God so loved us, we ought also to love one another.
(9) An other reason by comparison: if God so loved us, shall not we his children love one another?
(10) No man hath seen God at any time. If we love one another, God dwelleth in us, and his love is (g) perfected in us.
(10) A third reason: Because God is invisible, therefore by this effect of his Spirit, that is, by charity, he is understood to be not out of us, but united with us and in us, in whom he is so effectually working.
(g) Is surely in us indeed, and in truth.
(11) And we have seen and do testify that the Father sent the Son [to be] the Saviour of the world.
(11) He underlays this charity with another foundation, that is, faith in Jesus, which joins us indeed with him, even as charity witnesses that we are joined with him. Furthermore he testifies of Christ, as who had seen him with his eyes.
Whosoever shall (h) confess that Jesus is the Son of God, God dwelleth in him, and he in God.
(h) With such a confession as comes from true faith, and is accompanied with love, so that there is an agreement of all things.
And we have known and believed the love that God hath to us. (12) God is love; and he that dwelleth in love dwelleth in God, and God in him.
(12) A fourth reason: God is the fountain and wellspring of charity indeed charity itself: therefore whoever abides in it, has God with him.
(13) Herein is our love made perfect, that we may have boldness in the day of judgment: because (i) as he is, so are we in this world.
(13) Again (as before) he commends love, seeing that by our agreement with God in this thing, we have a sure testimony of our adoption, it comes to pass by this that without fear we look for that latter day of judgment, so that trembling and torment of conscience is cast out by this love.
(i) This signifies a likeness, not an equality.
There is no (k) fear in love; but perfect love casteth out fear: because fear hath torment. He that feareth is not made perfect in love.
(k) If we understand by love, that we are in God, and God in us, that we are sons, and that we know God, and that everlasting life is in us: he concludes correctly, that we may well gather peace and quietness by this.
(14) We love him, because he first loved us.
(14) Lest any man should think that that peace of conscience proceeds from our love as the cause, he goes back to the fountain, that is, to the free love with which God loves us although we deserved and do deserve his wrath. From this springs another double charity, which both are tokens and witnesses of that first, that is, that we love God who loved us first, and then for his sake our neighbours also.
(15) If a man say, I love God, and hateth his brother, he is a liar: (16) for he that loveth not his brother whom he hath seen, how can he love God whom he hath not seen?
(15) As he showed that the love of our neighbour cannot be separate from the love with which God loves us because this last gives rise to the other: so he denies that the other kind of love with which we love God, can be separate from the love of our neighbour: of which it follows, that they who say they worship God, and yet do not regard their neighbours lie shamelessly.
(16) The first reason taken from comparison: why we cannot hate our neighbour and love God, that is, because he that cannot love his brother whom he sees, how can he love God whom he cannot see?
(17) And this commandment have we from him, That he who loveth God love his brother also.
(17) A second reason, why God cannot be hated and our neighbour loved, because this same lawmaker commanded us both to love him and our neighbour.