“IN the free Covenant of Grace, or of the gospel, the first ground is our Mediator Jesus Christ, crucified also, and dead; or, which is the same in effect, the blood of the Mediator, the virtue whereof is twofold. The first serves to satisfy the justice and wrath of God for our sins, for the breach of that covenant of works. The second is, to purchase and merit a new grace and mercy of God for us. And this grace or mercy of God, obtained by the blood of the Mediator, is the second ground of the Covenant of Grace, whereby we stand reconciled unto God, and in grace with him. Wherefore the first immediate ground of the Covenant of Grace is God’s free favour or mercy, (whereby man’s misery is presupposed,) and not nature, or any good thing in it, for that all our natural goodness, after the breach of that covenant of works, is quite vanished; that is to say, nature, as touching holiness, justice, and wisdom, is utterly lost. For we are not to approve their judgment which say, that the freedom of will, that is, the goodness and holiness of nature, is much worn and weakened, as they speak, in this corrupt nature…”
“The first and principal grace promised in this covenant is righteousness; which must necessarily here have the first place, for after the breach of the covenant of works, that one first original justice, as they call it, was quite lost, and injustice did succeed into the place thereof. And this justice, which is here promised in the Covenant of Grace, is no inherent righteousness, as that original justice was, but is the righteousness of our Mediator Jesus Christ, which is ours by faith, and by the imputation of God. For which cause the Apostle calls it the righteousness of God; for without this imputative justice we cannot possibly stand before the tribunal of God, and by the imputation of this righteousness are we said to be justified before God. Next after this kind of righteousness, which is by imputation, there is another kind of inherent justice promised in the Covenant of Grace, even such a sanctity and goodness of nature as was lost in the fall of man, and this is but begun in this life, but perfected in another. And this inherent justice is nothing else but life eternal in us, begun, I say, in earth, and perfected in heaven. And this heavenly and spiritual life doth proceed from that righteousness of Christ, which is imputed unto us by faith. For that righteousness of Christ is effectual in us unto eternal life by the Spirit of Christ, who sanctifieth and quickeneth us.”
– Robert Rollock (c. 1555-1599), A Treatise of our Effectual Calling, Chapter III
Theologia est doctrina Deo vivendi per Christum - Theology is the doctrine of living unto God through Christ 