Thank you for your diligent work for the kingdom of God. I hope you understand and appreciate how your work has impacted the faith of countless people across the world.
My question has to do with the concept of God in Christianity, Islam, and Judaism. I am sure that you are aware of the current controversy over the “same God” comments of the professor at Wheaton College. As you can imagine this has caused a firestorm of debate between theologians, pastors and preachers. I understand from your work that you would say that while Muslims and Christians might worship the same God historically (the God of Abraham and Moses), their concept of God is fundamentally different (please correct me if I misunderstood your view). This refutes the “same God” idea because at the very core we worship a very different God even if the religions share a common background.
Several of the people who have defended the “same God” concept, however, have brought up the fact that Jews deny the concept of the Trinity and the deity of Jesus, and yet most Christians would say that Jews and Christians worship the same God. I agree that this seems hypocritical. Would you say that Jews and Christians worship the same God even if their idea of God (ex. the Trinity) is fundamentally different? If they deny the Trinity this would seem to be enough of a fundamental difference to say that we in fact do not worship the same God. This seems to me the only sound argument for defending the “same God” idea between Islam and Christianity. If we accept this then we either have to say that Christians, Jews, and Muslims all worship the same God or that all worship a different God entirely, regardless of historical background.
The question whether Muslims and Christians worship the same God raises a nest of perhaps unexpected philosophical difficulties, such that at the end of the day I think that this is not really the right question to ask.
Consider, for example, my friend and colleague Frank Beckwith’s attempt to answer this question (http://www.thecatholicthing.org/2015/12/17/do-muslims-and-christians-worship-the-same-god/). Beckwith tries to answer the question by appeal to the notion of reference. He wants to provide conditions under which different singular terms (like proper names) are co-referring (refer to the same thing). So, he asks, “what does it mean for two terms to refer to the same thing? Take, for example, the names ‘Muhammed Ali’ and ‘Cassius Clay.’ Although they are different terms, they refer to the same thing, for each has identical properties.”
Beckwith here lays out a sufficient condition for two terms to be co-referring:
1. If the referents of two terms have identical properties, then the terms refer to the same thing.
Beckwith then applies that condition to terms for God: “So the fact that Christians may call God ‘Yahweh’ and Muslims call God ‘Allah’ makes no difference if both ‘Gods’ have identical properties.” Thus,
1*. If the referents of “Yahweh” and “Allah” have identical properties, then the terms refer to the same thing.
Since Muslims, like Christians and Jews, are classical theists, Beckwith claims that the sufficient condition for co-reference is fulfilled.
But this is far too quick. For the obvious problem is that Yahweh and Allah do not have the same properties. Yes, Muslims and Christians embrace classical theism, a sort of generic monotheism. But the Muslim concept of God and the Christian concept of God are very different. It is not just that Christianity embraces Trinitarianism with respect to God and Islam Unitarianism, but the Muslim concept of God is in itself morally defective, as I have argued in my debates with Muslim theologians and apologists. The God of the Bible is an all-loving God, whose love is universal, impartial, and unconditional, while the God of Islam is not all-loving, but loves only Muslims and whose love is therefore selective, partial, and conditional. Therefore the sufficient condition stated in (1*) is not fulfilled.
So Beckwith appeals to a phenomenon much discussed by philosophers of language, namely, successfully referring to something by means of a false description. For example, suppose we observe a couple walking in the park and, noticing their behavior, I say to you, “Her husband is kind to her.” We both understand whom I’m talking about. Suppose, however, that you know that the man she is walking with is not, in fact, her husband and, moreover, that her husband is nasty and mean to her. In that case I have said something true of the man I intended to refer to even though my statement is literally false. So, Beckwith says, “The fact that one may have incomplete knowledge or hold a false belief about another person – whether human or divine – does not mean that someone who has better or truer knowledge about that person is not thinking about the same person.”
Granted; but that doesn’t imply that in every case involving false description they are thinking about the same person! In some cases, their conceptions may be so fundamentally different that their terms are not co-referring. Take Beckwith’s own example of the Virgin Birth and the Immaculate Conception. Imagine an ignorant Protestant who thinks that these terms refer to the same thing, namely, Jesus’ being born of a virgin. He might say that he and the Catholic believe the same thing, except that the Catholic just uses a different term for Jesus’ being born of a virgin.
Suppose he then finds out that when Catholics use the term “Immaculate Conception,” they are referring to Mary’s being born without original sin. Would the Protestant now continue to say that he and the Catholic are referring to the same thing by their respective terms? No, he would now say that the Catholic was referring to something else, since they have different conceptions of what these terms refer to.
So what about the God of the Bible and the God of the Qur’an? Is this just a case of referring to the same God under a false description or of referring to two different deities?
The problem is that
Beckwith hasn’t given us the necessary as well as the sufficient conditions for terms to be co-referring. He hasn’t told us what conditions must be met for two terms to be co-referring. So his argument that “Yahweh” and “Allah” are co-referring, despite the different conceptions of God involved, doesn’t go through, and his article ends too abruptly.
This is just the beginning of difficulties. A further wrinkle is that “worships x” is what philosophers call an intensional (as opposed to extensional) context, where the term “x” need not refer to anything at all (as in, e.g., “Jason worships Zeus”).  In an intensional context co-referring terms cannot be substituted without impacting the truth value of the sentence. For example, even though “Jupiter” may refer to the same god as “Zeus,” still Jason, a Greek, does not worship Jupiter and may have never even heard of the Roman god. So one cannot say that Abdul, a Muslim, worships Yahweh, even if “Yahweh” and “Allah” are co-referring terms.
In view of these difficulties, I prefer to avoid problems of reference altogether by asking instead about the Muslim and Christian concepts of God. The conceptions of God in Christianity and Islam are so fundamentally different that they are not the same God. Miroslav Volf, an evangelical theologian who, like Beckwith, defends the claim that Muslims and Christians worship the same God, acknowledges,
In addition to contesting the Trinity and the incarnation, Muslims also contest the Christian claim that God is love — unconditional and indiscriminate love. There is no claim in Islam that God ‘justifies the ungodly’ and no command to love one’s enemies. But these are the signature claims of the Christian faith. Take the redemption of the ungodly and the love of enemy out of the Christian faith, and you un-Christian it.
I wish that those who insist that Christians worship an altogether different God than Muslims latched on to this difference — that instead of wanting to ‘end’ Muslims they deem to be their enemies in the name of God, they would seek to embrace them in the name of Christ. If they did so, they would need to show how struggle against enemies is a way of loving them — an argument that many great theologians in the past were willing to make (https://www.washingtonpost.com/news/acts-of-faith/wp/2015/12/16/do-muslims-and-christians-worship-the-same-god-college-suspends-professor-who-said-yes/).
Volf rightly discerns how morally defective the Islamic conception of God is. I, for one, have emphasized this point, as he recommends, in my debates with Muslim thinkers. But I do not regard them, as Volf uncharitably suggests, as enemies. They have been deceived by Satan, who is the real enemy here. One way of loving Muslims is to explain honestly our differences, rather than to conceal them in shmoozey interfaith dialogue, and to argue for our point of view, just as the great theologians in the past did. I have found that such an approach wins the respect and even admiration of Muslims.
One final point: What about the Jewish and Christian concepts of God? Are they so different that they are not the same God? That depends on your perspective. The Christian does not reject the Jewish concept of God as the Muslim rejects the Christian concept of God. The Christian finds the same God of the Old Testament more fully revealed in the New Testament and looks for anticipations of the Son and Spirit in the Old Testament. By contrast the Muslim explicitly repudiates the concept of God found in the New Testament.
But if I were an Orthodox Jew, then I would say that Christians have a different concept of God and are worshiping a different God.
Look how certain Jews treated the apostle Paul. They regarded him as a heretic and pursued him from city to city across the Mediterranean in an attempt to kill him. Eventually, Christians were expelled from the synagogue. Once the doctrine of the Trinity emerged among the early church fathers, the break with Judaism became, from a Jewish perspective, unbridgeable.
So whether Muslims and Christians can be said to worship the same God is not the truly germane question. The question is which conception of God is true.
 For that reason, we should not say that Muslims are idolaters because they do not worship the true God, but that “Allah” has no referent in the real world; what they worship simply does not exist, anymore than Zeus exists.
by William Lane Craig | Submit your question to Dr. Craig