In reading through Volf’s chapter in Allah, I surprised to see some of the same polemical debates carried into current times–the same arguments and the same misunderstandings.
One large benefit from the questions from Muslims towards Christians with respect to the Trinity is that, much like the Trinitarian controversies faced in the Early Church, Christians are challenged to think carefully and articulate specifically about something that which is ultimately beyond words.
That being said, I’m left to wonder as we’ve talked about Trinitarian understanding, how much is this simply a roadblock that will only be overcome through faith? Is this at all similar to the faith required in Mohammad’s prophethood?
I hope I’m not giving the impression that we should cast reason aside; certainly, we delve deeper into the infinitely knowable nature of God’s essence as we do so. But isn’t faith the key to opening this journey into the mystery? If that is the case, how does this play out as we try to understand one another?
Islam & Christian-Muslim Relations, Hamaty 
I agree that faith is key and in some ways I think your reflection is in line with what D’Costa says. Much of our knowledge about God comes from revelation, and not natural theology.
LikeLike