This holy, spiritual, and supernatural Principle is the Gift of God. He is the sole Author, and efficient Cause of it.
Hence the new Birth is always ascribed to Him. The Saints are said to be born of God. To be born of the Spirit. Which were born, not of Blood, nor of the Will of the Flesh, nor of the Will of Man; but of God. That which is born of the Flesh, is Flesh:That which is born of the Spirit, is Spirit. So is every one that is born of the Spirit. God of his abundant Mercy begets us again. Of his own Will begat He us. This Principle is a good, and perfect Gift, which cometh down from above, from the Father of Lights. With respect to Faith, the Apostle asserts negatively, that it is not of ourselves: And he affirms positively, that it is the Gift of God. By Grace are we fared through Faith, that not of ourselves, it is the Gift of God. And declares to the Ephesians, that we are, as Saints, the Workmanship of God. For we are the Workmanship of God, created in Christ Jesus unto good Works. This Principle, therefore, is a divine Gift, and is not acquired, by those in whom it is. It is so the Gift of God, that the Subjects of it had not, nor could have the least causal Influence in its Production. For this Principle, is not only superior unto, and above all that was in them before, in its Nature; but also, it is absolutely contrary to the natural Disposition of their Minds. And, consequently, it must have been produced in them by divine Grace, without any concurrent Act of their Will therein, or in order thereunto. It is unreasonable to suppose, that one contrary, is capable of exerting Acts, which tend to the Production of another. Is not the Flesh contrary to the Spirit? It is. And is not the Spirit contrary to the Flesh? It is. And they counter-act one another perpetually. And, therefore, this holy, spiritual, and supernatural Principle, must be a divine Gift, in the most full, and absolute Sense. It is a new Life in the Soul, which was dead before. And it is as much the Gift of God, as Life is, which is communicated to a Man, who before, was dead naturally. As a Man who is naturally dead, cannot contribute to the Production of Life in himself: So such who are dead in Sin, can contribute nothing to the Production of a vital Principle of Holiness, in themselves. If God doth not graciously give to them such a Principle, they will eternally remain destitute of it: Or continue dead in Trespasses and Sins for evermore. For, as hath been before observed, they cannot possibly be assisted to acquire it. As a Man naturally dead cannot be enabled to acquire Life: So one who is dead in Sin, cannot be assisted to acquire this new, and heavenly Life.
--- John Brine – 1760 in London
“OF THE MERCY OF GOD”
Redemption itself is a signal instance of the mercy of God. Mercy resolved upon the redemption and salvation of the elect; being viewed as fallen in Adam, and as sinners, mercy provided a Redeemer and Saviour of them, and laid their help upon him; mercy called Christ to undertake the work of redemption, and engaged him in it; mercy sent him, in the fulness of time, to visit them, and perform it; mercy delivered them up into the hands of justice and death, in order to obtain it, and it is most illustriously glorified in it; "mercy and truth have met together", (Ps. 85:10) yea, Christ himself, in his love and pity, has redeemed his people (Isa. 63:9).
The forgiveness of sin is another instance of the mercy of God, to which it is frequently ascribed (Ps. 51:1; Dan. 9:9; Luke 1:77, 78). God has promised it in covenant, as the effect of his mercy; "I will be merciful to their unrighteousness" (Heb. 8:12). He has set forth Christ, in his purposes, to be the propitiation for the remission of sins; and has sent him, in time, to shed his blood for it, (Rom. 3:25) and it is the mercy of God, which is the foundation of hope of it; and encourages sensible sinners to ask, and through which they obtain it (Ps. 103:8; Luke 18:13; 1 Tim. 1:13).
The mercy of God is displayed in regeneration, to which that is ascribed in (1 Peter 1:3) and it is wonderful and special mercy, to quicken a sinner dead in trespasses and sins; to enlighten such that sit in darkness, and in the shadow of death; to deliver from the bondage of Satan those, that are led captive by him at his will; to snatch them as brands out of the burning, and save from everlasting fire; to bring men out of a pit, wherein there was no water, no relief and comfort, and in which they must otherwise die; and to reveal Christ to them, and in them, the hope of glory; and give them a good hope, through grace, of being forever happy. These are some of the great and good things which God does for his people in the effectual calling, having compassion on them.
Complete salvation, and eternal life itself, flow from the mercy of God; he saves, "not by works of righteousness, but according to his mercy", (Titus 3:5) and when he shall put his people into the full possession of salvation, then they shall find and obtain mercy in that day, even in the day of judgment, when they shall go into life eternal; and therefore are now directed to look unto the mercy of Christ for it, (2 Tim. 1:18; Jude 1:21).