When it comes to debates about the nature of the Lord's Supper, there's a curious hermeneutical tactic employed by the crowd that insists Jesus was speaking symbolically by saying, "dO yOu AlsO BeLiEve tHat JeSus iS a liTeRal dOor?" Let's break it down.

Their argument is, essentially, as follows:
1. Jesus speaks metaphorically elsewhere, therefore it is possible that He is speaking metaphorically here.
2. The absurd implications of interpreting Jesus literally prove that He is speaking metaphorically.

In other words, they are not engaging the actual text at all. Rather they are determining their theology of the Lord's Supper by:
1. Looking to passages that are not about the Lord's Supper.
2. Lording their presuppositions over the institution narratives.

Interestingly, this is the exactly same trick that liberal theologians use to justify their worthless theology. For example, liberal theologians will tell you that Adam and Eve are not historical people and that the creation account is not meant to be taken literally. Why?

Well, it's not based on any evidence in the actual creation account. Rather, they simply point to the non-literal bits of Scripture and say, "there's non literal stuff all over the place, so it's entirely possible that the creation account is not literal."

Then they impose their presuppositions on the text to protect themselves from the implications of Genesis being true history.

"If the creation account is actual history, then we'd have to reject evolution, an old earth, etc... And those things are obviously true, so therefore the creation account is a metaphor."

This the same trick they pull with the role of women in the church, sexuality stuff, salvation through Christ alone, etc... Why don't those passages mean what they say?

"Because there are passages that don't mean quite what they say, and I don't want these passages to mean what they say, therefore these passages don't mean what they say."

And again, this is exactly what the "dO yOu AlsO BeLiEve tHat JeSus iS a liTeRal dOor?" crowd is doing.

Even if we concede that Jesus is speaking metaphorically with "I am the door" (which He really isn't doing, but let's save that for another time), so what? The existence of other non-literal words from Christ isn't evidence that the Words of Institution are non-literal.

To prove that, you would need actual evidence from the institution narratives. But guess what happens when you point this out to dO yOu AlsO BeLiEve tHat JeSus iS a liTeRal dOor-ists? They quickly jump to "but the implications."

Is Jesus speaking in a parable? No. Does Jesus give any verbal indication that He's not speaking literally? No. BUT HE MUST BE because, if he's not, well, gross! If Jesus really means it, then that's:
1. Cannibalism
2. Romanism

And it's that second point, I think, that is really the unacceptable thing for them. And what a dangerous game that is. Take "this can't be true because Catholics teach it" a step further and you're with the Mormons and JWs denying the Trinity.

The moral of the story is that it is profoundly destructive to our theology to employ bad hermeneutics just because they let us preserve our presuppositions. There's far more joy to be found humbling ourselves before the Scriptures and letting them speak freshly each day.