A friend asked me to comment on this post:
1. A few preliminary comments. If you turn to Deut 6:4, it says: "Here, O Israel, the Trinity is false!"
Only it doesn't say that. It doesn't say anything directly about the Trinity. In context, it sets Yahweh in contrast to paganism.
2. As for Mk 12:28-29, Jesus reaffirms the Shema. What a surprise. Was anyone expecting Jesus to repudiate the Shema?
Here's some recently scholarship on Markan Christology:
Put succinctly then, Mark’s Jesus is the kyriotic Son inasmuch as he embodies the royal hopes surrounding a Davidic ruler and healer, who performs these same activities (and more) as a god-in-disguise. Functionally, Mark’s Jesus is characterized as though he were the embodiment of both Yahweh and his Davidic Messiah. This union of the divine and Davidic creates a characterization for audience members in which the Markan Jesus far surpasses anything known in Jewish cultural memory aside from Yahweh himself. The result is that, for sympathetic audience members, the Markan narrative creates its own scripts and forms its own cultural memory, in which Jesus is assimilated to both David and God as a divine and suffering messiah.
Looks far more promising for Trinitarians than unitarians. And that's just Mark's Gospel, which has the least developed Christology.
3. A final preliminary point: why are Muslims in the combox giving Bart Ehrman high fives for his claim that Markan Christology is unitarian?
Do Muslims think the Gospels are unitarian? If so, why do they reject the Gospels? Aren't the Incarnation and Trinity the primary stumbling blocks for Muslims? If they think the unitarian interpretation is correct, why don't they accept the Gospels? They can't have it both ways.
4. Now I'd like to quote and comment on some remarks a Muslim made:
If you saw an orange and you kept saying it’s an apple, the whole world would not change their language and their norm understanding for things because of what you invented by your tongue.
In fact, by this kind of playing and tampering, we can make everything is acceptable even if you worshipped idols. Just invented an odd understanding, and new language to describe that absurdity, and you would be fine.
I know some Christians out there wish to insist that the three Persons are not individual beings, but even with them, the question which was just asked can be posed. Could you share how you define the word “being”?
For now, I’ll propose a very simple definition (which others, including Christians, are free to reject): a being is a thing which exists (i.e. here the word “being” is treated almost like an active participle of the verb to be). On such a definition, a cat could be a being, and various parts of that cat (e.g. its bones, its organs) could also be considered beings (though beings of a sort different from the being which comprises them). But even if one did hold to this definition, and concluded that a cat is a single being comprising multiple beings of another sort, that would not mean one cat is actually multiple cats.
Analogously, do you consider yourself a being? Do you consider me a distinct being from you? If so, would that mean you are a polytheist? Or does the existence of multiple beings not automatically equate with the existence of multiple gods?
But the whole matter is about your trinity. Muslims are asking why? If each person is a being who is full God by himself, then by definition why can’t we say that you worship three gods?
Although your analogy is not right since I was arguing from christians’ perspective that they worship one being consists of three persons, yet are you saying that (each person) in the trinity is not god or it’s god?
As I know that you say each person is full God, so I’m asking what the real difference between you and polytheists except the terms that you use?!
He's responding to someone other than me. I might have phrased things differently than the person he's responding to. Still, this may be representative of how a reasonably intelligent Muslim attacks the coherence of the Trinity. So let's consider his objection.
Let's begin by formalizing his objection. It might go something like this: if B is identical to A, and C is identical to A, then B is identical to C (via A). That seems logically irrefutable. But what if that's deceptively simplistic? Identity is vexed issue in metaphysics.
Let's take a comparison. I'm going to use some Muslim examples to illustrate a point. So let's assume for discussion purposes that Islam is true. I will be arguing from Muslim assumptions.
Is the Quran one or many? Surely it can't be both. It must either be one or many. That's the same logic Muslims deploy against the Trinity.
Well, what is the Quran? Suppose I have a pile of objects on a table. I'm speaking to a Muslim. I show him a hardcopy of the Quran and ask him what it is. I presume he'll say, "That's the Quran!"
I then show him a CD-ROM of the Quran and ask him what it is. I presume he'll say, "That's the Quran!"
I then show him an audiobook of the Quran and ask him what it is. I presume he'll say, "That's the Quran!"
I then show him an electronic Quran (on my e-reader) and ask him what it is. I presume he'll say, "That's the Quran!"
I then show him a Braille Quran and ask him what it is. I presume he'll say, "That's the Quran!"
I then quote the Quran in sign language and ask him what it is. I presume he'll say, "That's the Quran!"
So, is this one Quran or six Qurans?
What about a lector who recites the Quran from a minaret. Isn't that the Quran?
There's a sense in which these are all one and the same Quran. Yet there's another sense in which the spoken word is not the written word, an ebook is not a CD-Rom, which is not an audiobook, which is not a hardcopy. So here's a case where two or more things can be both identical and distinct. They can all be identical with the Quran even though they are not identical with each other.
How is that possible? Well, we can say, in one respect, that the Quran is the message. The content.
Yet the same information can be encoded in different media. So in that respect, it's possible for B to be identical with A, and C to be identical with A, even though B and C are not identical with each other.
And we can carry the same principle back a few more steps. If Muhammad dictates a surah to a scribe, and the transcription is accurate, isn't that the Quran?
If Muhammad dictates the Quran from memory, and his memory is accurate, isn't his recollection of the Quran the Quran?
If Gabriel utters a surah to Muhammad, isn't Gabriel's utterance the Quran?
According to Sunni theology, there's an eternal Quran. An uncreated, heavenly exemplar.
Yet that's distinct from, say, Muhammad's memory of the Quran. Muhammad's memory of what Gabriel said isn't eternal. Rather, that's a mental copy. A mental representation of what he heard.
But let's take this back one step further: isn't there a distinction between the uncreated Quran and Allah's mind?
Does Allah think in Classical Arabic? Is Allah's cognition inseparable from human words? Was Allah unable to think before the development of Classical Arabic?
Or is the eternal Quran an Arabic translation that exists in Allah's mind? A translation, from thought into words, of Allah's nonverbal Quranic concepts? So how many Qurans are there?
• Hard copy. Print media
• Live recitation
• Sign language
• Transcription of Muhammad's dictation
• Muhammad's memory of Gabriel's revelations
• Gabriel's revelations
• The eternal Quran
• Allah's nonverbal concept of the Quran
Now, I'm not Muslim. I don't think Gabriel appeared to Muhammad. I was temporarily adopting a Muslim viewpoint for the sake of argument.
In addition, my point is not that this presents a direct analogy from the Trinity. That's not how I'd model the Trinity.
It does, however, illustrate that there's nothing inherently contradictory or nonsensical about saying individuals can be both distinct in some respect, yet identical in some respect. And there's nothing terribly esoteric about that distinction. I just drew that distinction in relation to the Quran.