3a. There is no cause of it out of God; there is no motive or inducement to it in them, no loveliness in them to excite it; all men by nature are corrupt and abominable; rather to be loathed than loved; and those that are loved, are no better than others, all being under sin; and are, “by nature, children of wrath, as others”; as deserving of that as those that are not loved, (Rom. 3:9; Eph. 2:3) what loveliness or beauty is in saints, is owing to the righteousness of Christ, imputed to them; which is that comeliness that is put upon them, whereby they are made perfectly comely; and to the sanctifying grace of the Spirit, whereby they are all glorious within, and appear in the beauties of holiness: so that all this is the fruit of the love of God, and not the cause of it. Nor can it be any love in them to God, that is the cause of his to them; for they had no love in them when Christ died for them; nor until regenerated by the Spirit of God; and when they love him, it is because he first loved them, (1 John 4:10, 19) and though Christ is said to love them that love him, and the Father is said to love them too; yet this must not be understood of the first love of God and Christ, unto them, nor of the first display of it; but of further and larger manifestations of it to them; and is descriptive of the persons who are most certainly and evidently the objects of their love; but not as being the cause of it, (Prov. 8:17; John 14:21, 23, 16:27). Nor are good works the cause of this love; for this, at least, in one instance of it, was before either good or evil were done, (Rom. 9:11, 12) and in other instances it broke forth towards them, and broke in upon them while they were yet in their sins, and before they were capable of performing good works, (Rom. 5:8; Titus 3:3, 4; Eph. 2:2-4) and how can it be thought, that since the best works of men are so impure and imperfect as to be reckoned as filthy rags, that these should be the cause of God’s love to men? no, even faith itself is not; that “is the gift of God”, and flows from electing love, and is a fruit and evidence of it (Eph. 2:8; Acts 13:48; Titus 1:1). God loves men, not because they have faith; but they have faith given them, because God loves them; it is true indeed, that “without faith it is impossible to please God”; that is, to do those things which are pleasing in his sight; but then the persons of God’s elect, may be, and are, well pleasing to God, in Christ, before faith, and without it. In short, the love of God purely flows from his good will and pleasure; who “is gracious to whom he will be gracious”, (Ex. 33:19) it is that pure river that proceeds out of the throne of God, and of the Lamb, as an emblem of sovereignty, (Rev. 22:1) as God loved the people of Israel because he loved them, or would love them; and for no other reason, (Deut. 7:7-8) in like manner he loves his spiritual and mystical Israel.
3b. The love of God is eternal, it does not commence in time, it is without beginning, it is from eternity: this is evident from the love of God to Christ, which was before the foundation of the world; and with the same love he loved him, he loved his people also, and as early, (John 17:23, 24) and from various acts of love to them in eternity; as the election of them in Christ, which supposes the love of them, (Eph. 1:4) the covenant of grace made with them, in which, grants of grace, and promises of glory, were made before the world began; and Christ was set up as the Mediator of it from everlasting: all which are strong proofs of love to them (2 Tim. 1:9; Titus 1:2; Prov. 8:22, 23).
3c. The love of God is immutable, unalterable, and invariable; it is like himself, “the same today, yesterday, and for ever”: and, indeed, God is love; it is his nature; it is himself; and therefore must be without any variableness, or shadow of turning. It admits of no distinctions, by which it appears to alter and vary. Some talk of a love of benevolence, by which God wishes or wills good to men; and then comes on a love of beneficence, and he does good to them, and works good in them: and then a love of complacency and delight takes place, and not till then. But this is to make God changeable, as we are: the love of God admits of no degrees, it neither increases nor decreases; it is the same from the instant in eternity it was, without any change: it is needless to ask whether it is the same before as after conversion, since there were as great, if not greater gifts of love, bestowed on the object loved, before conversion, as after; such as the gift of God himself, in the everlasting covenant; the gift of his Son to die for them when in their sins; and the gift of the Spirit to them, in order to regenerate, quicken, and convert them; heaven itself, eternal life, is not a greater gift than these; and yet they were all before conversion. There never were any stops, lets, or impediments to this love; not the fall of Adam, nor the sad effects of it; nor the actual sins and transgressions of God’s people, in a state of nature; nor all their backslidings, after called by grace; for still he loves them freely, (Hosea 14:4) for God foreknew that they would fall in Adam, with others, that they would be transgressors from the womb, and do as evil as they could; yet this hindered not his taking up thoughts of love towards them, his choice of them, and covenant with them. Conversion makes a change in them; brings them from the power of Satan to God, from darkness to light, from bondage to liberty; from fellowship with evil men to communion with God: but it makes no change in the love of God; God changes his dispensations and dealings with them, but never changes his love; he sometimes rebukes and chastises them, but still he loves them; he sometimes hides his face from them, but his love continues the same, (Ps. 89:29-33; Isa. 54:7-10) the manifestations of his love are various; to some they are greater, to others less; and so to the same persons, at different times; but love in his own heart is invariable and unchangeable.
3d. The love of God endures for ever; it is an everlasting love, in that sense, (Jer. 31:3) it is the bond of union between God and Christ, and the elect; and it can never be dissolved; nothing can separate it, nor separate from it (Rom. 8:35, 38, 39). The union it is the bond of, is next to that, and like it, which is between the three divine persons (John 17:21, 23). The union between soul and body, may be, and is dissolved, at death; but neither death nor life can separate from this; this lovingkindness of God never departs; though health, and wealth, and friends, and life itself may depart, this never will, (Isa. 54:10) whatever God takes away, as all the said things may be taken away by him, he will never take away this, (Ps. 89:33) having loved his own which were in the world, he loves them to the end, to the end of their lives, to the end of time, and to all eternity (John 13:1).
John Gill (1697 – 1771) Body of Doctrinal Divinity Book 1, Chapter 12, The Love of God