William Cunningham clarifies the confusion of that often stems from such a statement:
We would now make two to three observations, suggested by this account of the state of the question. First, the advocates of a limited or definite atonement do not deny, but maintain, the infinite intrinsic sufficiency of Christ’s satisfaction and merits. They regard His sufferings and death as possessed of value, or worth, sufficient to have purchased pardon and reconciliation for the whole race of fallen man. The value or worth of His sacrifice of Himself depends upon, and is measured by, the dignity of His person, and is therefore infinite. Though many fewer of the human race had been to be pardoned and saved, an atonement of infinite value would have been necessary, in order to procure for them these blessings; and though many more, yea, all men, had been to be pardoned and saved, the death of Christ, being an atonement of infinite value, would have been amply sufficient, as the ground or basis of their forgiveness or salvation. We know nothing of the amount or extent of Christ’s sufferings in themselves. Scripture tells us only of their relation to the law, in compliance with the provision of which they were inflicted and endured. This implies their infinity, in respect of intrinsic legal worth or value; and this, again, implies their full intrinsic sufficiency for the redemption of all men, if God had intended to redeem and save them. There have been some Calvinists who have contended that Christ’s sufferings were just as much, in amount or extent, as were sufficient for redeeming, or paying the ransom price of, the elect,—of those who are actually saved: so that, if more men had been to be pardoned and saved, Christ must have suffered more than He did, and if fewer, less. But those who have held this view have been very few in number, and of no great weight or influence. The opinion, however, is one which the advocates of universal atonement are fond of adducing and refuting, because it is easy to refute it; and because this is fitted to convey the impression that the advocates of a limited atonement in general hold this, or something like it, and thus to insinuate an unfavourable idea of the doctrine. There is no doubt that all the most eminent Calvinistic divines hold the infinite worth or value of Christ’s atonement,—its full sufficiency for expiating all the sins of all men.
A distinction was generally employed by the schoolmen, which has been often adverted to in this discussion, and which it may be proper to explain. They were accustomed to say, that Christ died sufficiently for all men, and efficaciously for the elect,—sufficienter pro omnibus, efficaciter pro electis. Some orthodox divines, who wrote before the extent of the atonement had been made the subject of full, formal, and elaborate discussion,—and Calvin himself among the rest,—admitted the truth of this scholastic position. But after controversy had thrown its full light upon the subject, orthodox divines generally refused to adopt this mode of stating the point, because it seemed to ascribe to Christ a purpose or intention of dying in the room of all, and of benefiting all by the proper effects of His death, as an atonement or propitiation; not that they doubted or denied the intrinsic sufficiency of His death for the redemption of all men, but because the statement—whether originally so intended or not—was so expressed as to suggest the idea, that Christ, in dying, desired and intended that all men should partake in the proper and peculiar effects of the shedding of His blood. Calvinists do not object to say that the death of Christ—viewed objectively, apart from His purpose or design—was sufficient for all, and efficacious for the elect, because this statement in the first clause merely asserts its infinite intrinsic sufficiency, which they admit; whereas the original scholastic form of the statement,—namely, that He died sufficiently for all,—seems to indicate that, when He died, He intended that all should derive some saving and permanent benefit from His death. The attempt made by some defenders of universal atonement to prove, that a denial of the universality of the atonement necessarily implies a denial of its universal intrinsic sufficiency, has nothing to do with the settlement of the state of the question, but only with the arguments by which the opposite side may be defended; and, therefore, I need not advert to it.
Secondly, It is not denied by the advocates of particular redemption, or of a limited atonement, that mankind in general, even those who ultimately perish, do derive some advantages or benefits from Christ’s death; and no position they hold requires them to deny this. They believe that important benefits have accrued to the whole human race from the death of Christ, and that in these benefits those who are finally impenitent and unbelieving partake. What they deny is, that Christ intended to procure, or did procure, for all men those blessings which are the proper and peculiar fruits of His death, in its specific character as an atonement,—that He procured or purchased redemption—that is, pardon and reconciliation—for all men. Many blessings flow to mankind at large from the death of Christ, collaterally and incidentally, in consequence of the relation in which men, viewed collectively, stand to each other. All these benefits were, of course, foreseen by God, when He resolved to send His son into the world; they were contemplated or designed by Him, as what men should receive and enjoy. They are to be regarded and received as bestowed by Him, and as thus unfolding His glory, indicating His character, and actually accomplishing His purposes; and they are to be viewed as coming to men through the channel of Christ’s mediation,—of His sufferings and death.
The truth of this position has been considered as affording some warrant for saying, in a vague and indefinite sense, that Christ died for all men; and in this sense, and on this account, some Calvinists have scrupled about meeting the position that Christ died for all men with a direct negative, as if they might thus be understood as denying that there was any sense in which all men derived benefit, from Christ’s death. But this position does not at all correspond with the proper import of what Scripture means when it tells us that Christ died for men. This, as we prove against the Socinians, implies that He substituted Himself in their room and stead, that He put Himself in their legal position, that He made satisfaction to God’s justice for their sins, or that He purchased redemption for them; and this, we contend, does not hold true of any but those who are actually at length pardoned and saved. The advocates of universal atonement, then, have no right to charge us with teaching that none derive any benefit from Christ’s death except those who are pardoned and saved; we do not teach this, and we are not bound in consistency to teach it. We teach the opposite of this; and we are not deterred from doing so by the fear lest we should thereby afford to those who are opposed to us a medium for proving that, in the proper scriptural sense, He died for all men, or that the leading and peculiar benefits which His death procured for men,—the benefits of salvation,—were designed or intended for all mankind.*
*Cunningham, W. (1864). Historical theology: A review of the principal doctrinal discussions in the Christian church since the apostolic age, Volume 2. (331–334). Edinburgh: T&T Clark.