Who is Jesus Christ? This is one of the questions that undoubtedly divides Christians and Muslims. Muslims say that Jesus was a prophet of God and a messenger of God. Christians affirm this, but say much more. Jesus Christ is more than a prophet, for he is God incarnate. He is God. We believe this, not because it readily makes sense to us, but because this is what the Injil teaches. For example, John 1:1 says, “In the beginning was the word and the word was with God and the word was God.” Jesus Christ is the Word of God. He was with God (thus there is some kind of distinction) and he was God (there is some kind of unity). We do not, however, believe in multiple Gods. There is one God. I believe this as strongly as any of my Muslim friends. To think otherwise is blasphemy.
But often, my Muslim friends just don’t see any reason to believe that Jesus is God. They don’t see why Jesus Christ has to be both man and God (an admittedly difficult thing to explain). I read the following answer by Sinclair Ferguson in his book, In Christ Alone: Living the Gospel Centered Life and thought it might be helpful for my Muslim readers to better understand why we think it is so important that Jesus is both God and man, even if you still disagree.
What makes this two-nature [God and man] Christology essential to the gospel? John’s answer [from the Gospel of John] is twofold:
1. Only God – the One through whom “all things were made” (John 1:3, cf. v. 10), in whom “was life” and “light” (John 1:4) – can reverse creation’s death and dissipate the darkness caused by sin.
2. But since that death and darkness are within creation, within man, the Word must become flesh in order to restore it from within. The Creator must enter His own creation, groaning as it is under the burden of alienation from Him.*
*Sinclair Ferguson, In Christ Alone: Living the Gospel Centered Life (Orlando: Reformation Trust Publishing, 2007), 13.

Obviously, as a Muslim I have theological objections to the Trinity, but I certainly agree that most Muslims don’t understand what the Trinity means for Christians. What I think few Muslims (quite inevitably) realize is that is that the doctrine of the Incarnation is a very effective way of bridging the psychological gulf between God–whose transcendence is awing–and his creation. Muslims, especially Sufis, bridge this gap in a sense in a more complex and indirect way. The Christian solution is very elegant and simple (which in itself proves nothing of course–life’s truths aren’t always simple).
One thing that a lot of Muslims don’t realize is how many subtle parallels there in spite of these obvious theological disagreements (e.g., as Sayyid Hossein Nasr has pointed out, the Quran serves a similar role to Muslims as Jesus, being a kind of incarnation of God’s will and both being of miraculous birth; and that’s not even getting into the widespread Sufi traditions that posit the Nur Muhammadiyya or Muhammadan Light, the notion that the world was created from Muhammad’s “light”, that Muhammad is the focal point of creation itself and its primary conduit for divine mercy). I’m not saying these theological differences are unimportant–Tawhid, monotheism, is the most important principle of Islam–but we have more in common than we often realize. And the fact that the Quran, which obviously condemns the Trinity in no uncertain terms, does not lump Christians in the same category as polytheists–Christians are given the same preferential status as the unquestionably monotheistic Jews–is very significant, in my view. Clear boundaries are drawn, yes, but for those who are able and willing to grapple with complexity and interior meanings there is much more to ponder, I think.
Not that I’m trying to imply that Christians don’t believe in a kind of monotheism. But the Chalcedonian notion of a triune godhead in hypostatic union isn’t easy for us Muslims to grok!
One more thing: One of the great ironies is that the most (to a traditional Muslim sensibilities) theologically objectionable parts of the NT (especially the Gospel of John) have striking similarities to Islamic mysticism. Again, bracketing the that pesky divinity thing, there are times when John’s discussion of the Logos reminds me of Sufi writings about Muhammad as the Preexistent Light of Creation, Insan Kamil (Perfect Man) and vice versa. That’s why many Muslims get really nervous with Sufism–it can *seem* to blur the line between God and Man.
Forgive me for yet another comment, but I should clarify something–when I wrote about “traditional Muslim sensibilities”, I should’ve written “exoterically-inclined Muslim sensibilities” or something along those lines. I don’t want reinforce that old cliche that Sufis as a whole are any less orthodox.
No forgiveness necessary for your many helpful comments. I should just let you write a few posts! I’d still love for you to write on “What is a Muslim?”
Thanks for sharing your thoughts here. You’re the first Muslim I’ve heard who said the Trinity is “very elegant and simple.” And thanks for affirming that Christians are monotheists!
Glad you found the observations useful, Dustin.
I’m not surprised, but then most Muslims have not had much exposure to Christians own views of the Bible and Christianiy (and vice versa in the case of most Christans vis-a-vis Islam). Also, even if I don’t necessarily agree with Christian beliefs, being American they’re not surrounded by an air of exoticism or stigma for me.