I now come to the third part of the mass, in regard to which, we are to explain how it obliterates the true and only death of Christ, and drives it from the memory of men. For as among men, the confirmation of a testament depends upon the death of the testator, so also the testament by which He has bequeathed to us remission of sins and eternal righteousness, our Lord has confirmed by His death. Those who dare to make any change or innovation on this testament deny His death, and hold it as of no moment. Now, what is the mass but a new and altogether different testament? What? Does not each mass promise a new forgiveness of sins, a new purchase of righteousness, so that now there are as many testaments as there are masses? Therefore, let Christ come again, and, by another death, make this New Testament; or rather, by innumerable deaths, ratify the innumerable testaments of the mass. Said I not true, then, at the outset, that the only true death of Christ is obliterated by the mass? For what is the direct aim of the mass but just to put Christ again to death, if that were possible? For, as the apostle says, “Where a testament is, there must also of necessity be the death of the testator” (Hebrews 9:16). The novelty of the mass bears, on the face of it, to be a testament of Christ, and therefore demands His death.

   Besides, it is necessary that the victim, which is offered, be slain and immolated. If Christ is sacrificed at each mass, He must be cruelly slain every moment in a thousand places. This is not my argument, but the apostle’s: “Nor yet that He should offer himself often;” “for then must He often have suffered since the foundation of the world” (Hebrews 9:25-26). 

The Holy Catholic Church (Book 4 of the Institutes) - John Calvin