Was there an element of grace in the CoW? If, as John Owen states, Adam had the Holy Spirit, was not this an indication of grace? Does this view constitute a "flattening of the COW and COG [that] will actually get you somewhere... where Christians should never tread"? What if divine grace was actually part of God's essential attributes? Should Christians really not go there?
Let's allow Dr. Richard A. Muller to provide some precision here:
C. Divine Grace and Favor
1. The grace of God in the thought of the Reformers. Although the Reformers held firmly to a doctrine of salvation by grace alone, virtually none of them wrote a separate treatise on grace—nor, indeed, is there a locus on grace in Musculus, Calvin, or Vermigli. Of the major Reformers of their era, only Melanchthon and Bullinger provided topical discussions of the grace of God. Still, the absence of extended discussions of “grace” as a divine attribute does not mark a radical point of discontinuity with the Reformed orthodox. The definitions and the polemics of the Reformers do understand grace in the ultimate sense as lodged or grounded in God—and not merely as a matter of divine favor exercised ad extra. Melanchthon’s definition is one of the few that refers grace strictly to the economy of salvation, understanding it as “the free remission of sins” or the free unmerited mercy of God. Bullinger, by way of contrast, looks as much to the nature of God as to the work of salvation, defining grace as “the favor and goodness of the eternal Godhead, wherewith he, according to his incomprehensible goodness, doth gratis, freely, for Christ’s sake embrace, call, justify, and save us mortal men.”508 Similarly, Calvin (whose full definitions of grace appear, not in the Institutes, but in the commentaries) identifies grace as the unmerited or undeserved goodness of God and insists on the absurdity of certain scholastic definitions of grace that identify it as “nothing else but a quality infused into the hearts of men: for grace, properly speaking, is in God; and what is in us is the effect of grace.”510 In addition, when Calvin understands the biblical text as referring “grace” restrictively to the saving work of God, he can offer the qualification that “the term grace denotes here not the favor of God, but by metonymy, the gifts that he bestows on men gratuitously”—and since “metonymy” is a figure of speech that names the effect for the cause, Calvin clearly assumes that the basic meaning of grace is the favor Dei itself.
2. The Reformed orthodox doctrine of the gratia Dei. Although by far the larger discussion of divine grace belongs to the soteriology of Reformed orthodoxy, the theologians of the late sixteenth and the seventeenth centuries also consistently place the gratia Dei among the divine affections. Divine grace, as indicated both in the doctrine of the divine attributes and in the developing Reformed covenant theology of the seventeenth century, is not merely the outward favor of God toward the elect, evident only in the post-lapsarian dispensation of salvation; rather is it one of the perfections of the divine nature. It is a characteristic of God’s relations to the finite order, apart from sin, in the act of divine condescension to relate to finite creatures. Beyond this, it is a characteristic of the divine being itself, at the very foundation of God’s relationship with finite, temporal beings. God, in other words, is eternally “capable of manifesting His benevolence to creatures apart form any merit”—“even if there were no creature” in existence.513 As is the case with the other divine attributes,
God’s Graciousness is an essential property, whereby he is in and of himself most gracious and amiable, Psalm 145:8. God is only gracious in and of himself, and whatsoever is amiable and gracious, is so from him.
Since grace is in God “affectively” as an affection of the will and its operates effectively in the creatures who are the objects of God’s favor, it refers both to the inward actus or capacity in God for gracious or favorable relation to the creature and to the outward relationship of God to creatures as characterized by the undeserved divine benevolence. Thus, gratia Dei is that perfection or attribute according to which God, out of a totally gracious and unmerited love, is conceived as willing to communicate himself to his creatures. Considered as affective, as ratione actus interni in Deo, grace is a propensity of the divine will—while considered as effective it is the gifts of the Spirit graciously given to us by God, either the ordinary gifts of faith, hope, and love or the extraordinary gifts bestowed upon the church for its edification. The former, more fully described, is God’s grace
by which he is induced to communicate himself to the creature, freely and of his own accord; not from desert or debt, or any other cause outside of himself; and not to add anything to himself, but for the benefit of the object of this grace. For grace is nothing else but unmerited favor; it is always opposed to merit.
The relationship between grace and love is, moreover, made explicit by the orthodox: “Grace is that by which God is capable of being loved in himself and by which he favors and blesses his creatures.” This distinction between the inward grace by which God favors the creature and the outward blessing of grace yields, also, a distinction between “decretive” and “executive” grace, modeled on the often-used distinction between the eternal decree and its execution in time, and indicating “the eternal purpose of God concerning our election before the foundation of the world” and exercise or execution in the calling, justification, and sanctification of the elect.520
This twofold distinction can also yield a threefold meaning of grace: it can indicate, with reference to the decree or the “affective” inward grace of God, “God’s favor, by which he chose us from eternity unto life,” and, with reference to the outward executive or effective grace, either the temporal favor granted when God receives us in Christ, or the further effects of grace, namely, the blessings bestowed upon believers in Christ. This latter division of the effective grace of God follows out the breadth of the biblical usage—where the word “grace” has several connotations. These, the Reformed indicate, need to be carefully defined in order to avoid misrepresentation.
The effective grace of God can be divided into two categories—the gift itself and the receipt of the gift. Brakel, without comment, identifies these categories with the older scholastic language of gratia gratis dans, grace giving graciously, and gratia gratis data, grace graciously given. Fully acknowledging the source of the distinction, Rijssen comments that the “scholastics” describe effective grace as gratia gratis faciens and gratia gratis data. He indicates specifically that Reformed orthodoxy can appropriate the older vocabulary, redefining it to conform to the principle of sola fidei: this grace given by God cannot make us agreeable to God except insofar as the grace and righteousness (justitia) of Christ imputed to us does so; or, better said, the gratia gratum faciens, “grace working graciously,” or, as it is sometimes called, gratia gratum dans, is the gracious favor of God that turns toward us, not on grounds of our merit, but because of the gracious work accomplished for us in Christ. The gratia gratis data, or “grace graciously given,” indicates all of the means necessary to salvation and all of the benefits of Christ that are given to us in this life. Grace can also be distinguished into sufficient and efficient grace, Wendelin notes, but the distinction is disputed by Maccovius.525
There is also good ground for concluding that the modern conception of “common grace” finds its root more in the period of Reformed orthodoxy that in the era of Calvin and his contemporaries, given that many of the orthodox theologians were willing to define the gratia Dei as a bounty or graciousness extending to all creation. While God is gracious to all, his grace is particularly bestowed upon those who are his in Christ: “God’s free favor is the cause of our salvation, and of all the means tending thereunto, Rom. 3:24 & 5:15, 16; Eph. 1:5, 6 & 2:4. Rom 9:16; Titus 3:5, Heb. 4:16; Rom 6:23; 1 Cor. 12:4, 9. The gospel sets forth the freeness, fulness, and the powerfulness of God’s grace to his Church, therefore it is called the Gospel of the grace of God, Acts. 20:24.” This grace is such that it is given freely without desert and it is “firm and unchangeable, so that those which are once beloved, can never be rejected, or utterly cast off, Psalm 77:10.”
God’s effective grace given to us indicates all the gifts bestowed by the Spirit. Thus, in Rijssen’s analysis, the principle of justification by faith has caused the equation of the scholastic terms gratia gratis data and gratia gratis faciens—for the orthodox, forensic understanding of justification relates all righteousness to Christ and all virtue in the believer to the imputation of Christ’s righteousness and the consequent bestowal of gifts by the Spirit. The medieval categories enter, here, by way of clarification of doctrine: Rijssen both finds them useful as ways of describing the effective grace of God and senses the need for clarifying their application. Had not Rome continued to distinguish between gratia gratis data as the initial gift and gratia gratis faciens as the subsequent gift contingent on acceptance of just grace, Rijssen might well have omitted mention of the terms altogether: the point of his argument is that the terms are two ways of looking at the same thing.
The Arminians, too, mistake the meaning of God’s grace. Leigh calls them “patrons of man’s free will, and enemies of God’s free grace.” They claim that a man can come to merit God’s grace and that God gives “effectual grace” to all men, even to “the wicked which shall never be saved, to Judas as well as to Paul.” The Arminians, it seems, would forget that “effectual grace” is grace which obtains an effect!
The doctrine of God’s grace is, therefore, a doctrine of great practical import, in that it moves men to seek God’s favor:
The holy Patriarchs often desired to find grace in the eyes of the Lord. It is better than life to him that hath it; it is the most satisfying content in the world, to have the seal firmly settled in the apprehension of God’s goodness to him in Christ. It will comfort and stablish the soul in the want of all outward things, in the very hour of death. It is attainable; those that seek God’s face shall find him.
Leigh, even in this presentation of the divine attributes, takes the opportunity to develop a view of Christian life seeking the divine grace. Consciousness of one’s own sinfulness, meditation upon the law, consideration of “the gracious promises of God” and of “the grace of God in Christ,” confession of sin “with full purpose of amendment,” and pray for grace:
This stays our hearts when we apprehend our own unworthiness … We should acknowledge that all grace in us doth come from him the fountain of grace, and we should go boldly to the throne of grace, and beg grace of him for ourselves and others, Heb. 4:16. Paul in all his Epistles saith, grace be unto you. We should take heed of encouraging ourselves in sin, because God is gracious; this is to turn God’s grace into wantonness. We should frequent the Ordinances, where God is graciously present, and ready to bestow all his graces on us; the word begets grace, prayer increaseth it, and the Sacraments seal it.
Related to God’s grace are a series of other affections that appear variously in the Reformed orthodox theology—patience, long-suffering, compassion, condescension. Patience and longsuffering are the willingness of God to moderate “his anger toward creatures, and either defers punishment or for a moment withholds his wrath.”
God is Patient, Psalm 103:8; Job 21:7. God’s patience is that whereby he bears the reproach of sinners and defers their punishments; or it is the most bountiful will of God, whereby he doth long bear with sin which he hateth, sparing sinners, not minding their destruction, but that he might bring them to repentance. See Acts 13:18.
Even so God both endures “with much longsuffering” the sins of the reprobate and, at the same time, is patient with the elect prior to their conversion, willing their repentance rather than their immediate destruction because of sin. It is, thus, “the most bountiful will of God not suffering his displeasure suddenly to rise against his creatures offending, to be avenged of them, but he doth warn them beforehand, lightly correct and seek to turn them unto him.”535 The divine compassion, similarly, is the disposition of God to deliver creatures from their misery. It is manifest when “the object of the divine goodness of love [is] involved in misery, such as man who is a sinner and subject to death.” God’s humility or condescension, “by which God descends to our capacity, and graciously provides for our weakness,” is exemplified in “God’s familiar conversing and conference with Moses and Abraham interceding for Sodom, with David and others, and especially the incarnation of Christ.” The point very much reflects the assumption of the Reformers, particularly evident in Calvin, that God consistently accommodates himself to human capacity, both ontically and noetically: namely, God condescends or accommodates himself in order to relate to finite humanity, and he also does so in the form of his revelation in Scripture. This point of continuity, including its emphasis on the incarnation as the preeminent example of divine condescension, is significant if only because it is typically overlooked by the older scholarship.538
 Muller, R. A. (2003). Post-Reformation Reformed Dogmatics: The Rise and Development of Reformed Orthodoxy; Volume 3: The Divine Essence and Attributes (pp. 569–574). Grand Rapids, MI: Baker Academic.