When talking about the Lord’s Table, the first observation to make is that the command is “Take and eat,” not “Take and explain.” A life of obedient Table observance is necessary; the explanation, while theologically important, is really just something to argue about over a cold beer—very secondary by comparison.
The second observation is that it can’t possibly be wrong to simply observe the Table as we’re taught in the New Testament. When I serve someone the bread, I tell them “This is the body of Christ, broken for you.” I say this because Jesus said this. I do not explain further, because Jesus didn’t. It can’t be wrong to just do what Jesus did. (Or what Paul laid down, following Christ’s example.) Now, it’s possible that various alterations and elaborations are also ok (and note that Paul doesn’t quite do exactly what Jesus did either). But it can’t be wrong to just stick very closely to the biblical examples we’re given. (And as a practical matter when you’re celebrating the Table with people from multiple churches, sticking very closely to the biblical text avoids a lot of sticky difficulties.)
The third observation is that it’s possible to waaaaay overdo the search for an explanation. Aquinas tried to explain the realities of the Table in Aristotelian terms, which sounds a bit precious to modern ears. The contemporary equivalent would be someone setting out to explain the Table through a clever application of quantum mechanics. (“See, in the first three dimensions, it’s bread, but in the 17th dimension, it’s the body…”) Um, no. Let’s not.
So a minister is well within his rights to say what the New Testament says, stop there, and decline to comment further. In sensitive company, that’s often exactly what I do.
But since we’re all friends here, let’s crack a cold one and chat a little. I’d say we’re pretty well stuck with some kind of real presence. The alternative to believing in Christ’s real presence at the Table is believing in His real absence, and that won’t do. A Corinthian abusing the Table can’t be guilty of the body and blood of the Lord if the body and blood of the Lord are not present.
Of course the bread and wine remain bread and wine, symbols of Christ’s body and blood, but let us not forget that there is a class of symbols that accomplish what they signify. When I gave my wife a ring, in the presence of witnesses, with the words, “With this ring I thee wed…” — the ring is a symbol, all right. But it is a symbol that accomplishes what it signifies.
Likewise, in a way that I flatly decline to speculate about, I maintain that the bread and wine are symbols of the presence of Christ that accomplish what they signify. In them, Christ is truly present, and through eating and drinking, He is present in you. You are the body of Christ, because you are what you eat. You want to know how that works in detail? Way above my pay grade, man. I’m just the server, not the chef.
I’d recommend John Williamson Nevin’s work for further reading on this.