John Gill emphasizes that while no one has seen God in His fullness, we are called to express our love for God through our love for one another. He explains that God's presence dwells in those who love each other, reflecting the Spirit's work in their lives. Gill further clarifies that God's love is perfect and unchanging, while our love for Him and others is a growing and sincere expression of faith. The sermon highlights that true love is demonstrated through actions, not just words, and that our love for fellow believers is a reflection of our love for God.

Ver. 12. No man hath seen God at any time,.... The same is said by the Evangelist John, Joh 1:18; but here it is observed with a different view, and upon another account; there it signifies that no man has seen and looked into the counsels and designs of God, and been able to make a discovery and declaration of his mind and will, his love and grace, and which is there ascribed to the Son of God, See Gill on "Joh 1:18"; but here the sense is, that whereas God is invisible in his nature, and incomprehensible in his being and perfections, so that there is no coming to him, and seeing of him, and conversing with him in a familiar way, and so not of loving him as he is in himself, and ought to be loved, as one friend sees, converses with, and loves another, and finds his love increased by sight and conversation; then we ought to love the saints and people of God, who are visible, may be seen, come at, and conversed with, see 1Jo 4:20; for this clause stands among the arguments and reasons for brotherly love: if we love one another God dwelleth in us; not as he does in his Son, by union of nature; nor as in heaven, by the displays of his glory; nor as in the whole world, by his omnipresence and power; but by his Spirit, and the communications of his love, and by his gracious presence and communion, which he indulges the saints with; for such who love one another, as they appear to have the Spirit of God, of which that grace is a fruit, so they are by the Spirit built up a fit habitation for God, and by which Spirit he dwells in them; and such may expect the presence of God, for they who live in peace, the God of love and peace shall be with them: and his love is perfected in us; not that love of God, with which he loves his people; for that admits of no degrees, and is not more or less in itself, or in his heart; but is always invariably and unchangeably the same, and is full, complete, and perfect in his own breast, as it was from all eternity; and does not pass by degrees, or gradually rise from a love of benevolence to a love of complacency and delight, or increase as our love does to him and to one another, on which it has no dependence: nor is this love perfected in the saints in this life; that is to say, they have not perfect knowledge and enjoyment of it; nor have they all the effects of it bestowed upon them, and applied unto them; the perfection of it, in this sense, will be in heaven: but the love with which God is loved is here designed; and it is called his, because he is both the object and the author of it; and this is no effect as to degrees; yea, sometimes, instead of abounding and increasing, it goes back, it is left, and waxes cold; and it will not have its completion till the saints come to heaven, and then it will be in its full perfection and glory, when faith and hope shall be no more: but the sense is, that this grace of love is sincere and hearty, and without dissimulation; it is unfeigned love; and it is in deed and in truth, and not in word and in tongue only; and this appears to be so, by the love which is shown to the brethren, the children of God; so that love to God in the saints is perfected by love to the brethren, just in such sense as faith is made perfect by works, Jas 2:22, that is, is made to appear to be genuine, right, and true.