OK, so we have our taxonomy below with two additions and one clarification.
In the Receptionism vs. Consecrationism debate we have an Agnostic option: We just don't know whether or not our Lord's Body and Blood are present after the consecration while the host remains on the paten before a communicant receives the host.
Likewise, an Agnostic option for the debate within the ranks of Consecrationists (Durationist vs. Cessationist) as to the continuance of the Real Presence after everyone has communed and there remain consecrated elements in paten and chalice: We just don't know whether or not that is our Lord's Body and Blood or not.
And the clarification for Fr. Petersen: An open question is something the Scriptures do not speak to at all, or in such a passing manner that they give no clear answer; for an "unclear answer" is no answer at all.
I was sorry to see that we had no Receptionist commentators. This is a widely held belief in the Missouri Synod, and is certainly the explict and official teaching of WELS. If any advocates of Receptionism want to take up their cause in the comments, that would be an important and worthy debate and you will, at least by the editors, be treated with respect and seriousness.
Likewise, we didn't have anyone take up the Cessationist stance - though a couple advocated Agnosticism: that the Bible does not clearly answer this question and therefore it is an open question.
So the live issue for Gottesdienst readers (apparently all Consecrationists) would seem to be this. Many Lutheran parishes reserve consecrated elements for distribution to the sick, or to be used at the next week's Communion service. While these are thus being reserved, are they in fact the Body and Blood of Christ?
I think the answer is an unequivocal Yes. The Scriptures are clear. Jesus says, "Take drink, FOR this is my blood" (Matt. 26:28). It is thus Jesus' blood when those Words of the Lord are brought to those elements. And the Word of the Lord endures forever. We have no Word from Jesus that would overturn those Words of Institution. Certainly time does not diminish his Word. Certainly human action (leaving the building, singing the Nunc Dimittis) do not change his Word either.
So my question to the Cessationists is: where is your clear Word of God overturning the Words of Institution?
My question to Agnostics on this question is more complicated, because I can't ask them to prove a negative. They contend that the Scriptures don't answer this question or don't answer it clearly. Well, tell me more about that. What's wrong with the Bible passages I quoted above? How did I misquote them? How on earth could the Scriptures be understood otherwise than I have understood them?
But there is something more: you just can't be Agnostic on this one. You can be agnostic on the Pertpetual Virginity of our Lady because that doctrine has no translation into the life of the Church. That is, a Lutheran who believes Mary and Joseph had children will not live his Christian life any differently that one who believes that she remained a Virgin until her dormition. Furthermore, it's pious to think one or the other. It's no slander on her to say she was a normal, married woman. And it's no slander to say she had a higher calling and gift, celibacy.
But you can't be Agnostic on whether or not the host in Fr. Eckardt's tabernacle is the Body of Christ. That is, since congregations are, in fact, reserving the consecrated elements that forces a decision. This is not an abstract question in a book. If the Body and Blood of Christ are there, and are not treated with their due honor but instead called mere bread and wine: that's the blasphemy of unbelief. If it's just bread and wine in that Tabernacle and folks are genuflecting, imagining that it is the Body and Blood of Christ, then those people are committing idolatry.
The binary choice emerges, as the philosophers say. This is a real pastoral issue. It can't just be "pious opinion" - it's not pious to think that a piece of bread is the Body of Christ if it isn't, it's idolatry. And it's certainly not pious to treat the Body of Christ like a mere piece of bread.
Here's the rub. Luther and Melanchthon struck a deal over this between themselves and with the other participants in the Wolferinus episode. The deal was this: since we're not all agreed, and since this Unavoidable Either/Or question arises if there are Reliquae - let us have no Reliquae. Once there was no Reliquae it all became Hypothetical - and folks could afford the charity of being Agnostic. "What if there were Reliquae? Would they be the Body of Christ? Maybe so - or maybe not. Doesn't matter though - think what you want, it's all hypothetical." To men of peace with bigger fish to fry, like Luther and Melanchthon (and their peace loving heirs like Sasse) this was a perfect solution - it was a churchmanly deal struck for the right reasons.
But their deal has fallen apart, for good or ill, and we can't turn back the clock. We have Reliquae now, all over the Synod. Treating these Reliquae like the Body and Blood of Christ because they might be is no solution: for you also might be committing idolatry. Agnosticism is not an option now that this is a real, rather than hypothetical problem.
So - Octoberfest is coming. You'll walk into St. Paul's and the sanctuary lamp will be lit: will you kneel to the Body and Blood of Christ or just bow to an altar where they once rested? I can't see a third, agnostic option. . . well, you could yell at Fritz for being so divisive and disrupting the Luther-Melanchthon pact, I guess.