1 John 4:9

In this was manifested the love of God towards us
The love of God here spoken of, and instanced in, is not his general love to all his creatures, which is shown in the make of them, and in the support of them in their beings, and in his providential care of them, and kindness to them; but his special love towards his elect, and which was before it was manifested; it was secretly in his heart from everlasting, and did not begin to be at the mission of Christ into the world, but was then in a most glaring manner manifested: there were several acts of it before, as the choice of them in Christ, the appointment of him to be their Saviour, and the covenant of grace made with him on their account; these were more secret and hidden; but now the love and kindness of God appeared, broke forth, and shone out in its glory; this is a most flagrant and notorious instance of it, in which it is exceedingly conspicuous; this is a most clear proof, a plain and full demonstration of it:

because that God sent his only begotten Son into the world;
the sender is God the Father, who is distinguished from the Son that is sent; of which act of sending, (See Gill on Romans 8:3) and (See Gill on Galatians 4:4); and for him, who is that God against whom we have sinned, and is that lawgiver that is able to save, and to destroy, and of purer eyes than to behold iniquity, to send his Son to be the Saviour of sinful men is an amazing instance of love; and which appears the more manifest, when it is observed that it is "his only begotten Son" that is sent; of which (See Gill on John 1:14); and the place he was sent into is the world, where his people are, and where their sins are committed, he came to expiate; and where he was treated with great indignity and contempt, and suffered many things, and at last death itself: the end of his mission was,

that we might live through him;
who were dead in Adam, dead in sin, and dead in law, and could not quicken themselves; nor obtain eternal life for themselves, by their performances. Christ came, being sent, that they might have life, and that more abundantly than Adam had in innocence, or man lost by the fall; and accordingly they were quickened together with him; when he was quickened, after he had been put to death, they were virtually and representatively quickened and justified in him; and in consequence of his death and resurrection from the dead, they are regenerated and made spiritually alive, and live unto righteousness; and through his righteousness wrought out for them, and imputed to them, they are in a legal sense alive unto God, and alive and comfortable in their own souls, living by faith on Christ, and have a right and title to eternal life; and which they also have through him, and which is chiefly intended here; for the design is not only that they may live spiritually and comfortably here, but eternally hereafter.