I am writing this theological point for you since many have asked what the difference between transubstantiation and what we as Lutherans believe are true about the Eucharist. Below you will find a succinct but at time perhaps difficult to follow theological discussion of the differences and similarities. I hope that you at least find it helpful in some form!

Transubstantiation is the Roman Catholic understanding of Holy Communion. This term was adopted by the Council of Trent (1545-1563) as the official dogmatic teaching of the church. Transubstantiation is the belief that a change of the elements of bread and wine take place. The bread and the wine cease to be and are changed into Christ’s body and blood. This is a simplified explanation of a very complex argument that spans many pages.

What Luther argued was not that transubstantiation was wrong but that trying to explain how the bread and wine are the body and blood of Christ is a human mistake. For Luther the mystery of the incarnation is tied directly into the mystery of how the Eucharistic bread and wine are the body and blood of Christ. Luther in his 1528 treatise on the Lord’s Supper in fact says, "If you can explain how Christ is both fully God and man I will explain how the bread and wine are his body and blood." For Luther, the elements at the table are both bread and Christ’s body.

Transubstantiation says that when the bread is revealed to be Christ’s body, the substance of bread is destroyed and we are left with Christ’s body; the same then is true of the wine. Luther’s incarnational understanding of the Eucharist could not confess this because when Christ took on humanity, his Godhood was not destroyed but co-existed within his being. Thus the bread and the wine co-exist with Christ’s very real physical body in the bread and wine. What transubstantiation calls an accident, that the bread and wine still look and taste like what they were before, Luther says they still are bread and wine but are also the body and blood of Christ.

Unfortunately, this argument from Luther garnered Protestants like Calvin and Zwingli to make arguments that the bread and wine only represent Christ’s body and blood or that Christ is spiritually present in the elements. Luther stands even firmer against these teachings than he does the papists. In fact, Lutherans and Roman Catholics believe in Christ’s "Real Presence" in the sacrament. (By "Real Presence" of course Luther and the Catholics mean physical body.) Luther believes that Christ is bodily present in the elements and to say that Christ is spiritually present or that the bread and wine represent Christ’s body and blood is heresy and worthy of being excommunicated from the Sacrament.

Now that I hope you have a better understanding of the difference in doctrine between Lutherans and Roman Catholics I want to set talk about why this kind of knowledge and debate is important for the church. This kind of debate helps us to understand more fully what it is Christ gives us. Jesus said, "Do this in remembrance of me" and since then, mainline church have been confident of what the "this" is but have debated over the physicality of Christ’s presence in the elements. In a rational and imperfect human mind it is impossible to imagine how this could be true, which is why Luther says, "If you can tell me how Christ is both fully God and fully human I will tell you how the bread and wine are also Christ’s physical body and blood" and yet we do not argue about the dual natures of Christ but simply believe. Ultimately, all our debate and even the doctrine of transubstantiation was done in an effort to help the faithful wrap their minds around so great a mystery. It may not always be perfect but these debates have assisted the faithful by in the end strengthening their faith and helping them to wrap their heads around the awesome mysteries of this God we worship. Ultimately, when all the debate is over, the only argument we truly need is, "because Jesus said so"!

You will notice how throughout my explanation I never used the word "becomes" or "is made" to refer to the consecration of Christ’s body and blood. Why is that? Certainly we believe that the pastor is necessary to perform the Eucharistic actions in order for the bread and the wine to be Christ’s body and blood? You see, Luther believed that if the pastor using the Eucharistic actions (elevation, prayer, and fraction) make the bread and wine Christ’s body and blood then you are admitting transubstantiation is valid. Instead what Luther argued is that the Eucharistic actions are necessary for the priest to reveal the bread and wine as Christ’s body and blood. Again this fit into the incarnational thinking for Luther. Was not this illegitimate child from Nazareth named Jesus also the Son of God? Yet, he was not known as such until John the Baptist revealed it at the waters of the Jordan having it revealed to him from on high.

And so it is with this ordinary bread and wine that the word reveals through the authorized speaking of the priest that this bread and wine is Christ’s body and blood. Christ’s body and blood could not function in that capacity until it was revealed through the speaking of the priest in the mass. And so as Lutherans who adhere to the Lutheran confessions this is what we believe, teach, and confess is true about the Lord’s Supper.

You may be asking yourself than why aren’t the jars of wine kept sacred or the hosts kept sacred that have not been consecrated? The simple answer is because those have not been revealed as Christ’s body and blood, so while we can speculate that they will be revealed as such or that we even intend for them to be revealed as such, it is not a 100% guarantee until the pastor gets behind the altar and says, "This is my body given for you". Then and only then do we know for sure that those elements are Christ’s body and blood.