Do Muslims and Christians Worship the Same God?
[This essay was originally submitted as an assignment for a course in Catholic & Islamic theology at the University of Notre Dame.]
Introduction
About a year ago, an Internet dust-up led to the most recent flurry of speculation about whether Christians and Muslims worship the same God.[1] Despite the fact that some Protestant Christians answer “no,” the traditional Christian answer—reiterated magisterially as recently as 1965 by the Second Vatican Council[2]—has been a resounding “yes.” In this essay, I intend to show that the teaching given by Vatican II is no mere pastoral rephrasing in support of the Church’s historical position,[3] nor an accident of history,[4] but rather one that cogently reaffirms the philosophical and theological foundations which have consistently underlaid this teaching for more than 1,000 years.
The Teaching’s Philosophical Foundation
Two preliminary issues need to be addressed before we can make fruitful use of the biblical and theological data at hand; the first is to clarify the terminological matter of asking the right question, and the second is to gain an understanding of the semantic concept of the referent.
In popular discourse, the question “Do Christians and Muslims worship the same God?” is often subtly (or not-so-subtly![5]) sidestepped in favor of answering the question “Do Christians and Muslims believe the same things about God?” instead.[6] The answer to this second question is manifestly “no”—among other things, Muslims deny the Trinity and the Incarnation, which are Christianity’s central theological claims.[7] However, a negative answer to the latter question does not necessarily require a negative answer to the former.
This is where we need to bring in the semantic concept of the referent: namely, the person or thing to which someone is referring. Here it is important to note that even though two observers might have different beliefs about someone or something, both can still be referring to the same fundamental reality (a.k.a. both can have the same referent). For example, Jack may point to a shining object in the sky that he believes to be a satellite; Jill may point to the same object under the assumption that it is a distant star. If you asked them what they believed about the nature and composition of that point of light in the sky, they would give you very different answers (manmade electronic device vs. enormous ball of nuclear fusion plasma), but each of them would still be referringto the same reality, regardless of whether it were actually a satellite or a star or something else entirely.
The same can be said of Christians and Muslims in regard to the God they purport to worship: despite their differing beliefs about God’s nature in Himself and His activity in history, there is and can only be one Being—one referent—Who is the omnipotent, omniscient creator and sustainer of everything that exists.
The Teaching’s Biblical Basis
The Bible records a useful example of this kind of “mistaken identity” phenomenon in the speech that St. Paul’s delivers at the Athenian areopagus in Acts 17:22-34. Among the many altars the Athenians had erected in honor of their pagan gods, St. Paul finds one addressed “To an Unknown God.” Always a clever rhetorician, St. Paul takes advantage of this referential anonymity to present his own case for the one true God, insisting to the Athenians that the deity they referred to as “unknown” is in fact the creator and sustainer of all: “What therefore you worship as unknown, this I proclaim to you. The God who made the world and everything in it, being Lord of heaven and earth…gives to all men life and breath and everything. And…he is not far from each one of us, for ‘in him we live and move and have our being’” (Acts 17:23-25, 27).
Having shown with this example that there can be continuity of referent even for the natural religion of the pagans, I also want to emphasize the scriptural case for continuity of referent between Christians and the Jewish people. The apostles, not to mention the Lord Himself, claimed that He was sent by (and in fact is) the same God Who had been revealed to the Jewish people,[8] and the early Church Fathers agreed.[9] This uniformity of God’s identity is important, because while some Protestants affirm that Christians, Jews, and Muslims have a “same God, different understanding”[10] viewpoint with regard to one another, others who deny that Muslims and Christians worship the same God will “bite the bullet” when pressed and deny that Jews and Christians worship the same God, too.[11](Unfortunately, the adverse theological implications of this bifurcation of the Jewish and Christian God are beyond the scope of this brief paper.) While of course the New Testament by definition has to address the question of its continuity with the Old Testament, the New Testament obviously has nothing to say about Islam, which wouldn’t arise until more than half a millennium after the earthly life of Jesus and His first followers. In order to ascertain what Christian theologians thought about Islam itself, we need to skip ahead[12] to the 11th century.
Theologians Throughout History
In 1076, Pope Gregory VII penned a letter to Anzir, the Muslim king of Mauritania,[13] in which he asserts that “we [Muslims and Christians] believe and confess one God, although in different ways, who call him the Creator of the ages and the Governor of this world.”[14]
A couple of centuries later (c. 1264), having recently finished the Summa Contra Gentiles, the great St. Thomas Aquinas sat down to write a pamphlet in response to questions raised by “the Cantor of Antioch” (a fellow music director!) entitled On the Reasons of the Faith: Against the Saracens, Greeks, and Armenians: to the Cantor of Antioch.[15] Despite otherwise being an adept takedown of Islamic objections to Christianity, St. Thomas avoids charging the Muslims with things like “demon worship” or “idolatry.” On the contrary, we find this charmingly polemical work’s seventh chapter (on the fittingness-but-not-strict-necessity of Christ’s suffering and death for our salvation) notably grouping together the adherents of the three Abrahamic religions (as well as furnishing the title for my paper!) in a line that says, “we argue presently [about divine fittingness vs. necessity] against those who say they are worshippers of God, whether Muslims or Christians or Jews.”
Commenting on Jeremiah’s prophecy that “all men shall know the Lord, from the least of them to the greatest,”[16] the 16th-century counter-Reformer St. Robert Bellarmine says in his 1586 Disputations on the Controversies of the Christian Faith that “the Gentiles have been converted to the faith, and also the Jews themselves and the Turks [a.k.a. Muslims, who], although they are impious, yet worship the one God.”[17] His contemporary Francisco Suárez, a prolific Jesuit priest famous for his commentaries on metaphysics and legal philosophy, opined in a treatise on law that Muslims should indeed be counted among those “who adore only the one true God.”[18]
While perhaps someone could argue that Pope Gregory VII was minimizing his theological differences with King Anzir for the sake of political expediency, it seems much harder to suggest that the same could be said for St. Thomas Aquinas in a work of apologetics, St. Robert Bellarmine in a gloss on sacred Scripture, and Fr. Suárez in a treatise on law.
Conclusion
Therefore, I believe that I am warranted in positing that Catholic theologians have principled reasons for maintaining that Muslims and Christians do direct their adoration, worship, and prayers, to the selfsame one, true God.As I have demonstrated, Catholic theologians throughout history were not making their claims about Islamic worship of God simply out of concern for pastoral or political sensitivity, but rather precisely because there is sufficient philosophical (referential) and theological overlap to substantiate the assertion that—despite Islam’s many, egregious theological errors downstream of this issue—Muslims and Christians alike do indeed “adore the one God, living and subsisting in Himself; merciful and all- powerful, the Creator of heaven and earth.”[19]
[1] See e.g. the following video presentations from spring and summer of 2025:
Joe Heschmeyer, “Do Muslims and Christians Worship the Same God?” YouTube video by Shameless Popery, posted April 29, 2025, https://youtu.be/whBernptSkM?si=4tfi4EZG1ZqJldrz.
Jimmy Akin, “Do Muslims Worship God?” YouTube video by Jimmy Akin, posted February 17, 2025, https://youtu.be/KjVpp2Q-VgI?si=EjfRA_ODyz-RCxmc.
Trent Horn, “Do Christians and Muslims Worship the Same God? (My Take)” YouTube video by The Counsel of Trent, posted July 3, 2025, https://youtu.be/vuDH-16f_aQ?si=M1sZ1K_2bFk8z7kU.
Gavin Ortlund, “Do Muslims and Christians Worship the Same God?” YouTube video by Gavin Ortlund, posted June 27, 2025, https://youtu.be/orp9uwwhnAY?si=mA7OuLXZf8LFnngm.
[2] See Lumen gentium §16 and Nostra aetate §3 (as discussed in class).
[3] Contra a distinguished scholar of my acquaintance, who suggested that the teaching of Vatican II was not a matter of “philosophical overlap” between Christian and Islamic theologies, but instead a pastorally sensitive way of giving a “God’s-eye view” of God’s own relationship to humanity.
[4] Commentors on the history of Vatican II note that the post-World War II Church wanted to address the issue of anti-Semitism in light of the devastating tragedy of the Holocaust, but on account of secular political tensions in the Middle East felt that they could not be seen to be offering words favorable to the Jewish people while remaining silent on the status of the Muslim community. See e.g. O’Mahony, Anthony. “Catholic Theological Perspectives on Islam at the Second Vatican Council.” New Blackfriars 88, no. 1016 (2007): 385–98. http://www.jstor.org/stable/43251149.
[5] As in Dr William Lane Craig, “Do Christians and Muslims Worship the Same God?” YouTube video by drcraigvideos, posted June 16, 2016, https://youtu.be/bAvO_hH6OAY?si=Il6z2n_psficfF3H&t=97; Got Questions Ministries, “Do Christians and Muslims worship the Same God?” YouTube video by Got Questions Ministries, posted February 2, 2021, https://youtu.be/40FS9DBbG4k?si=qTknDsOCSCFkj54u.
[6] For the helpful distinction between these two questions I am indebted to Catholic Answers apologist Joe Heschmeyer in the video mentioned in footnote 1.
[7] On the preeminence and antiquity (c. AD 180) of these two distinctively Christian beliefs, see e.g. St. Irenaeus of Lyons, Against HeresiesI.10.1-2, in The Ante-Nicene Fathers: Translations of the Writings of the Fathers Down to A.D. 325, Alexander Roberts and James Donaldson, eds., Vol. I pp. 330-331, accessed online at https://ccel.org/ccel/schaff/anf01/anf01.ix.ii.xi.html.
[8] See John 8:58, John 20:17, Acts 3:13, and especially Stephen’s speech to the council in Acts 7 (this lattermost is by itself an excellent summary of the content of the first two-thirds of our course this semester!).
[9] See e.g. St. Augustine of Hippo, Of True Religion (Henry Regnery Company, 1964) 11, accessed online at https://ia903105.us.archive.org/12/items/st.augustineoftruerelilgion/St.%20Augustine%20of%20true%20relilgion_text.pdf.
[10] Miroslav Volf summarizes Martin Luther’s view this way in Allah: A Christian Response, 183.
[11] See e.g. Evangelical pastor Jon Benzinger’s reply in the video below, which itself is a perfect example of how the answer to this question can go awry when descriptions and referents are falsely equivocated.
Jon Benzinger, “Do Jews, Muslims, and Christians Worship the Same God? | Ask Redeemer” YouTube video by Redeemer Bible Church AZ, posted June 17, 2021, https://youtu.be/73hdx6uJwCM?si=RCGDAGZGl3AbvqYs.
[12] And we are skipping – it’s not as though Christians had nothing to say about Islam during the intervening four hundred years, but this is a short paper…
[13] Explicit reference is made to this letter in the footnote of Nostra aetate §3. The Latin text of the letter can be found in Patrologia Latina, comp. Jacques-Paul Migne (Belgium, 1878), Vol. 148, Col. 450-451, accessed online at https://archive.org/details/patrologiaecurs02unkngoog/page/n228/mode/2up.
[14] English translation taken from Sam Shamoun, “Pope Gregory VII, Muslims, and God,” Answering Islam, accessed July 17, 2026, https://answeringislam.blog/pope-gregory-vii-muslims-god/#latin-text.
[15] St. Thomas Aquinas, De Rationibus Fidei: Ad Cantorem Antiochenum, accessed online at https://aquinas.cc/la/en/~DeRatio.
[16] Jeremiah 31:34.
[17] St. Robert Bellarmine, Disputations on the Controversies of the Christian Faith, trans. Peter L.P. Simpson, Volume I, Book III, Chapter 10, accessed online at https://www.aristotelophile.com/Books/Translations/BellarmineControversyOne.pdf?ref=answeringislam.blog.
[18] See Francisco Suarez Opera omnia, Volume XII, Disputation 18, Section 4, Number 9, p. 451, accessed online at https://books.google.com/books?id=aCcNAAAAYAAJ&printsec=frontcover&lr=#v=onepage&q&f=false.
[19]Nostra aetate §3.