From 1555 to 1558, during the reign of Queen Mary (aptly called “Bloody Mary”), 288 English Protestants were burned at the stake for their opposition to the Roman church. Out of this number 55 were women and 4 were children. The primary issue over which these martyrdoms turned was the doctrine of transubstantiation.
Over and over the Protestant members of the Reformed Church of England were asked a variation on the following question as related by John Rogers:
” I was asked whether I believed in the sacrament to be the very body and blood of our Saviour Christ that was born of the Virgin Mary, and hanged on the cross, really and substantially? I answered, ‘ I think it to be false. I cannot understand really and substantially to signify otherwise than corporally. But corporally Christ is only in heaven, and so Christ cannot be corporally in your sacrament.’ “-Fox in loco, vol. iii. p. 10l, edition, 1684.
The doctrine in question was the real presence of the body and blood of Christ in the consecrated elements of bread and wine in the Lord’s Supper. Did they, or did they not believe that the body and blood of Christ were really, that is corporally, literally, locally, and materially, present under the forms of bread and wine after the words of consecration were pronounced? Did they or did they not believe that the real body of Christ, which was born of the Virgin Mary, was present on the so-called altar so soon as the mystical words had passed the lips of the priest? Did they or did they not? That was the simple question. If they did not believe and admit it, they were burned. 
Bishop J.C. Ryle explained why Christian men cannot embrace the false doctrine of transubstantiation:
Grant for a moment that the Lord’s Supper is a sacrifice, and not a sacrament . . . You spoil the blessed doctrine of Christ’s finished work when he died on the cross. A sacrifice that needs to be repeated is not a perfect and complete thing. You spoil the priestly office of Christ. If there are priests that can offer an acceptable sacrifice to God besides Him, the great High Priest is robbed of His glory. . . . You overthrow the true doctrine of Christ’s human nature. If the body born of the virgin Mary can be in more places than one at the same time, it is not a body like our own….
So while I believe that something more significant than mere recollection occurs at the celebration of the Eucharist, I cannot conclude that the Lord’s Supper is a sacrifice, nor that it involves the very body and very blood of our Savior. It is a memorial, and in its celebration we join the ranks of a great cloud of witnesses who have often paid much more dearly than we for the right to celebrate our Lord’s once and final act of atoning sacrifice on our behalf.