The following Calvin quote is given by Norman Geisler in Chosen But Free (page 156-157, 1st edition; pages 161-162, 2nd edition):
Eternal Predestination of God IX.5
Mark 14:24. This is my blood- I have already warned, when the blood is said to be poured out (as in Matthew) for the remission of sins, how in these words we are directed to the sacrifice of Christ’s death, and to neglect this thought makes any due celebration of the Supper impossible. In no other way can faithful souls be satisfied if they cannot believe that God is pleased in their regard. The word many does not mean a part of the world only, but the whole human race: he contrasts many with one, as if to say that he would not be the Redeemer of one man, but would meet death to deliver many of their cursed guilt. It is incontestable that Christ came for the expiation of the sins of the whole world“.
Geisler’s Interpretation: The “many” for whom Christ died means the whole human race
Geisler utilizes this alleged quote from Calvin’s treatise, The Eternal Predestination of God. Unfortunately, the majority of this quote doesn’t appear in that treatise, but is rather from one of Calvin’s commentaries on the Gospels. Hence, the quote is somewhat of a fabrication: only the last sentence is from The Eternal Predestination of God. To prove this, first read through Calvin’s comment on Mark 14:24 below. I have bolded the text used by Geisler. Observe how the sentence “It is incontestable that Christ came for the expiation of the sins of the whole world” is completely absent.
Mark 14:24. This is my blood. I have already remarked that, when we are told that the blood is to be shed—according to the narrative of Matthew—FOR THE REMISSION OF SINS, these words direct us to the sacrifice of the death of Christ, without the remembrance of which the Lord’s Supper is never observed in a proper manner. And, indeed, it is impossible for believing souls to be satisfied in any other way than by being assured that God is pacified towards them.
Which is shed for many. By the word many he means not a part of the world only, but the whole human race; for he contrasts many with one; as if he had said, that he will not be the Redeemer of one man only, but will die in order to deliver many from the condemnation of the curse. It must at the same time be observed, however, that by the words for you, as related by Luke—Christ directly addresses the disciples, and exhorts every believer to apply to his own advantage the shedding of blood Therefore, when we approach to the holy table, let us not only remember in general that the world has been redeemed by the blood of Christ, but let every one consider for himself that his own sins have been expiated.
Where is the sentence “It is incontestable that Christ came for the expiation of the sins of the whole world”? It is found in Calvin’s treatise, The Eternal Predestination of God. How did this happen? Did Geisler deliberately fabricate this quote? My judgment is no, it is probably not deliberate, it is rather sloppy scholarship. I went back and checked the source Geisler pulls from: R.T. Kendall’s book Calvin and English Calvinism to 1649. A section of a lengthy footnote on page thirteen reads as follows:
…‘The word many’, Calvin says, ‘does not mean a part of the world only, but the whole human race’. Comm. Mark 14:24. It is ‘incontestable that Christ came for the expiation of the sins of the whole world’. Concerning the Eternal Predestination of God (1961) (hereinafter called Predestination), 148.”
If Geisler utilized Kendall here, what seems to have happened is that whoever compiled this quote ignored a period and thought Kendall was quoting from only one source, when in fact he was quoting from two. However, when republishing this quote, Geisler (or someone) must have knowingly went and added a fuller context to the quote from Calvin’s comments on Mark 14:24, and simply added the sentence in the extra sentence. Interestingly, Calvin’s comment on Mark 14:24 is cited elsewhere in Chosen But Free, and the reference given is to Calvin’s comment on Mark 14:24, so obviously Geisler must be aware of the correct reference, minus the added sentence.
The section from The Eternal Predestination of God is worth quoting at length. Calvin is responding to Georgius (a universalist) on unlimited atonement:
Georgius thinks he argues very acutely when he says: Christ is the propitiation for the sins of the whole world; and hence those who wish to exclude the reprobate from participation in Christ must place them outside the world. For this, the common solution does not avail, that Christ suffered sufficiently for all, but efficaciously only for the elect. By this great absurdity, this monk has sought applause in his own fraternity, but it has no weight with me. Wherever the faithful are dispersed throughout the world, John extends to them the expiation wrought by Christ’s death. But this does not alter the fact that the reprobate are mixed up with the elect in the world. It is incontestable that Christ came for the expiation of the sins of the whole world. But the solution lies close at hand, that whosoever believes in Him should not perish but should have eternal life (Jn 3.15). For the present question is not how great the power of Christ is or what efficacy it has in itself, but to whom He gives Himself to be enjoyed. If possession lies in faith and faith emanates from the Spirit of adoption, it follows that only he is reckoned in the number of God’s children who will be a partaker of Christ. The evangelist John sets forth the office of Christ as nothing else than by His death to gather the children of God into one (Jn 11.52). Hence, we conclude that, though reconciliation is offered to all through Him, yet the benefit is peculiar to the elect, that they may be gathered into the society of life. However, while I say it is offered to all, I do not mean that this embassy, by which on Paul’s testimony (II Cor 5.18) God reconciles the world to Himself, reaches to all, but that it is not sealed indiscriminately on the hearts of all to whom it comes so as to be effectual. As for his talk about no respect of persons, let him learn first what the term person means, and then we shall have no more trouble in the matter.
If in fact Geisler got this quote from Kendall’s footnote, it should be immediately pointed out that Kendall has taken the quote out of context. Frederick Leahy explains,
“…those who appeal to Calvin’s remarks on the “all” and “world” passages have been less than fair to him, at times, quoting selectively and even out of context. Such manipulation results in distortion. Thus Kendall quotes, out of context, from “Concerning the Eternal Predestination of God,” it is “incontestable that Christ came for the expiation of the sins of the whole world.” In context Calvin’s intent becomes clear. He is discussing 1 John 2:2:
Wherever the faithful are dispersed throughout the world, John extends to them the expiation wrought by Christ’s death. But this does not alter the fact that the reprobate are mixed up with the elect in the world. It is incontestable that Christ came for the expiation of the sins of the whole world. But the solution lies close at hand, that whosoever believes in Him should not perish but should have eternal life (Jn. 3:15). For the present question is not how great the power of Christ is or what efficacy it has in itself, but to whom He gives Himself to be enjoyed.
When Calvin’s statement, in italics above, is wrested from its context, it can convey a meaning opposite to the Reformer’s intention.”
 CBF 156-157. Emphasis by Dr. Geisler.
 John Calvin, Commentary on The Harmony of The Gospels Vol. 3, in The Comprehensive John Calvin Collection (Ages Digital Library, 1998).
 R.T Kendall, Calvin and English Calvinism to 1649, (Waynesboro: Paternoster Press, 1997), 13. Emphasis by Kendall.
 John Calvin, Concerning the Eternal Predestination of God, 148-149. The full context of this quote is available on line at: http://www.reformed.org/documents/calvin/calvin_predestination.html.
 Frederick S. Leahy, “Calvin and the Extent of the Atonement,” Reformed Theological Journal 8 (November 1992), 60.