A friend of mine (who will remain anonymous), recently brought to my attention the following excerpt from William Cunningham, Historical Theology, vol. 1, Sec. III.—Conversion—Sovereign and Efficacious Grace (all that follows is Cunningham, not me)
The controversy between Augustine and his opponents turned, as we have said, to a large extent, upon the nature and import, the necessity, grounds, and results of that grace of God, which, in some sense, was universally admitted to be manifested in preparing men for heaven. That a certain character, and a certain mode of acting, in obedience to God's law, were in fact necessary, in order to men's attaining final happiness, and that men were in some sense indebted to God's grace or favour for realizing this, was universally conceded. It was conceded by Pelagius and his immediate followers, and it is conceded by modern Socinians; but then the explanation which these parties gave of this grace of God, which they professed to admit, made grace to be no grace, and practically made men, and not God, the authors of their own salvation, which the Socinians, consistently enough, guarantee at length to all men. With the original Pelagians and the modern Socinians, the grace of God, by which men are, in this life, led to that mode of acting which, in fact, stands connected with their welfare in the next,—(for even Socinians commonly admit some punishment of wicked men in the future world, though they regard it as only temporary),—consists in these two things: First, the powers and capacities with which He has endowed man's nature, and which are possessed by all men as they come into the world, along with that general assistance which He gives in His ordinary providence, in upholding and aiding them in their own exercise and improvement of these powers and capacities; and, secondly, in the revelation which He has given them to guide and direct them, and in the providential circumstances in which He may have placed them. This view of the grace of God, of course, assumes the non-existence of any such moral corruption attaching to men, as implies any inability on their part, in any sense, to obey the will of God, or to do what He requires of them; and, in accordance with this view of what man is and can do, ascribes to him a power of doing by his own strength, and without any special supernatural, divine assistance, all that is necessary for his ultimate welfare. This view is too flatly contradictory to the plain statements of Scripture, and especially to what we are told there concerning the agency of the Holy Ghost, to have been ever very generally admitted by men who professed to receive the Bible as the word of God; and, accordingly, there has been a pretty general recognition of the necessity, in addition to whatever powers or capacities God may have given to men, and whatever aids or facilities of an external or objective kind He may have afforded them, of a subjective work upon them through special supernatural agency; and the question, whether particular individuals or bodies of men were involved more or less in the errors of semi-Pelagianism, or taught the true doctrine of Scripture, is, in part, to be determined by the views which they have maintained concerning the nature, character, and results of this special supernatural agency of God, in fitting men for the enjoyment of His own presence.
Even the original Pelagians admitted the existence of supernatural gracious influences exerted by God upon men; but then they denied that they were necessary in order to the production of any of those things which accompany salvation, and held that when bestowed they merely enabled men to attain them more easily than they could have done without them; while they also explicitly taught that men merited them, or received them ^as the meritorious reward of their previous improvement of their own natural powers. An assertion of the necessity of a supernatural gracious work of God upon men's moral nature, in order to the production of what is, in point of fact, indispensable to their salvation, has been usually regarded as necessary to entitle men to the designation of semi-Pelagians,—a designation which comprehends all who, while admitting the necessity of a supernatural work of God, come short of the full scriptural views of the pounds of this necessity, and of the source, character, and results of the work itself. The original Pelagian system upon this point is intelligible and definite, and so is the scriptural system of Augustine; while any intermediate view, whether it may or may not be what can, with historical correctness, be called semi-Pelagianism, is marked by obscurity and confusion. Leaving out of view the proper Pelagian or Socinian doctrine upon this subject, and confining our attention to the scriptural system of Augustine on the one hand, and, on the other hand, to those confused and indefinite notions which fall short of it, though not to such an extent as the doctrines of the Pelagians and the Socinians, we would remark that it is conceded upon both sides: First, that before men are admitted into heaven they must repent and believe in the Lord Jesus Christ, and lead thereafter a life of new obedience; and, secondly, that men have a moral nature so far tainted by depravity, that this indispensable process cannot in any instance be carried through without a supernatural gracious work of God's Spirit upon them.
These two propositions embody most important and fundamental truths, clearly and fully taught in Scripture, and essential to a right comprehension of the way of salvation. Men who deny them may be justly regarded as refusing to submit to the authority of God's word, and as rejecting the counsel of God against themselves; while, on the other hand, men who honestly and intelligently receive them, though coming short of the whole scriptural truth in expounding and applying them, may be regarded as maintaining all that is fundamental upon this subject; by which I mean,—in accordance with the common Protestant doctrine of fundamentals as brought out in the controversy with the Church of Rome,—that some men who have held nothing more than this have afforded satisfactory evidence that they themselves were born again of the word of God, and have been honoured as the instruments of converting others through the preaching of the gospel. But while this is true, and ought not to be forgotten, it is of at least equal importance to observe, that many who have professed to receive these two propositions in the general terms in which we have stated them, have given too good ground to believe that this professed reception of them was decidedly defective either in integrity or in intelligence,—have so explained them, or rather explained them away, as to deprive them of all real meaning and efficacy, and practically to establish the power of man to save himself, and to prepare for heaven, upon the ruins of the free grace of God, which is manifested just as fully in the sanctification as in the justification of sinners. And hence the importance and necessity of clearly and definitely understanding what is the scriptural truth upon these subjects, lest we should be deceived by vague and indefinite plausibilities, which seem to establish the grace of God, while they in fact destroy it. Defective and erroneous views upon this subject are usually connected with defective and erroneous views in regard to the totality of the moral corruption which attaches to men by nature, and of their consequent inability to do anything that is really spiritually good. It is manifest that any error or defect in men's views upon this subject will naturally and necessarily lead to erroneous and defective views of the nature, character, and results of that gracious work of God, by which man is led to will and to do what is good and well-pleasing in His sight.
When those who admit in general the necessity of a gracious work of God's Spirit upon men, in order to their repenting and believing the gospel, have yet erroneous and defective views upon the subject of divine grace, they usually manifest this by magnifying the power or influence of the truth or word of God,—by underrating the difficulty of repenting and believing,—by ascribing to men some remains of moral power for effecting these results, and some real and proper activity in the work of turning to God,— and hy representing the work of God's Spirit as consisting chiefly, if not exclusively, in helping to impress the truth upon men's minds, or, more generally, rendering some aid or assistance to the original powers of man, and to the efforts which he makes. It is by such notions as these, though often very obscurely developed, insinuated rather than asserted, and sometimes mixed up with much that seems sound and scriptural, that the true doctrine of tbe gracious work of God in the conversion of sinners has been often undermined and altogether overthrown. These men have, more or less distinctly, confounded the word or the truth—which is merely the dead instrument—with the Spirit, who is the real agent, or efficient cause of the whole process. They have restricted the gracious work of the Spirit to the illumination of men's understandings through the instrumentality of the truth, as if their will did not require to be renewed, and as if all that was needful was that men should be aided intellectually to perceive what was their true state and condition by nature, and what provision had been made for their salvation in Christ, and then they would certainly repent and believe as a matter of course, without needing specially to have the enmity of their hearts to God and His truth subdued. They have represented the gracious work of the Spirit chiefly, if not exclusively, as co-operating with men, ind aiding them in the work for which they have some natural capacity, though not enough to produce of themselves the necessary result, as if there was little or no need of preventing or prevenient grace, or grace going before, in order that man may work or act at all in believing and turning to God. These men are usually very anxious to represent faith in Jesus Christ as to some extent the work of men's own powers, the result of their own principles; and Augustine admits that he had some difficulty in satisfying himself for a time that faith was really and properly the gift of God, and was wrought in men by the operation of His Spirit, though this doctrine is very plainly and explicitly taught in Scripture. Much pains have been taken to explain how natural and easy saving faith is, to reduce it to great simplicity, to bring it down as it were to the level of the lowest capacity,—sometimes with better and more worthy motives, but sometimes also, we fear, in order to diminish, if not to exclude, the necessity of a supernatural preventing work of God's Spirit in producing it. And then, as repentance and conversion, as well as the whole process of sanctification, are beyond all doubt inseparably connected with the belief of the gospel, the way is thus paved for ascribing to man himself some share in the work of his deliverance from, depravity, and his preparation for heaven.
One of the most subtle forms of the various attempts which have been made to obscure the work of God's Spirit in this matter, is that which represents faith as being antecedent—in the order of nature at least, though not of time—to the introduction or implantation of spiritual life into the soul of man, dead in sins and trespasses. This notion is founded upon these two grounds: first, upon a misapprehension of the full import of the scriptural doctrine, that man is dead in sin,—as if this death in sin, while implying a moral inability directly to love God, and to give true spiritual obedience, to His law, did not equally imply a moral inability to apprehend aright divine truth, and to believe in the Lord Jesus Christ; and, secondly, upon a misapplication or perversion of the scriptural principle, that men are born again of the word of God through the belief of the truth,—as if this, while no doubt implying that the truth has been effectually brought to bear upon the mind before the process of being born again has been completed, so that the man is in the full exercise of new spiritual life, implied, moreover, that this efficacious operation of the truth must precede, in the order of nature, the whole work by 'which the Spirit originates the process of vivification; and the object and tendency of this notion, based upon these two grounds, are to produce the impression that men, through believing, are able to do something towards making themselves, or at least towards becoming, spiritually alive, and thereby superseding to some extent the necessity of a supernatural work of God's Spirit in a point of primary and vital importance, intimately connected with the salvation of men. Man is dead in sin; the making him alive, the restoring him to life, is represented in Scripture as, in every part of the process, from its commencement to its conclusion, the work of God's Spirit. The instrumentality of the truth or the word is, indeed, employed in the process; but in the nature of the case, and in accordance with what is clearly taught in Scripture, there must, antecedently—at least in the order of nature, though not of time—to the truth being so brought to bear upon men's minds as to produce instrumentally any of its appropriate effects, be a work of God's Spirit, whereby spiritual life is implanted, and a capacity of perceiving and submitting to the truth, which had been hitherto rejected, is communicated,—a capacity which, indeed, previously existed, so far as concerns the mere intellectual framework of man's mental constitution—the mere psychological faculties which he possesses as being still a man, though fallen—but which was practically useless because of the entire bondage or servitude of his will, which required to be renewed, and could be renewed only by the immediate agency of God's Spirit.