Is Catholicsm and Islam compatible?


Ergo, if we separate out the “office” of God and the “Person(s)” holding that office, you would have to admit, would you not, that Christians and Muslims do not agree about the nature of the Godhead at a very fundamental level? They could not be said to recognize, respect or worship the same God because of those fundamentally discordant views – remembering that, in reality, the “office” of God and the Person(s) holding that office are indistinguishable from each other.


Perhaps, going down this road many times before simply means you have been missing the obvious.

G K Chesterton in Why I Am Catholic wrote…

Catholicism is not ritualism; it may in the future be fighting some sort of superstitious and idolatrous exaggeration of ritual. Catholicism is not asceticism; it has again and again in the past repressed fanatical and cruel exaggerations of asceticism. Catholicism is not mere mysticism; it is even now defending human reason against the mere mysticism of the Pragmatists. Thus, when the world went Puritan in the seventeenth century, the Church was charged with pushing charity to the point of sophistry, with making everything easy with the laxity of the confessional. Now that the world is not going Puritan but Pagan, it is the Church that is everywhere protesting against a Pagan laxity in dress or manners. It is doing what the Puritans wanted done when it is really wanted. In all probability, all that is best in Protestantism will only survive in Catholicism; and in that sense all Catholics will still be Puritans when all Puritans are Pagans.


Notice how this relates to our current topic. Simply replace the referent God with the referent Catholicism and change a few verbs here and there in the current thread.

Some people love Catholicism and others hate or are oblivious to it. Would we claim it is the SAME Catholicism that all of these people are referring to? Clearly there is a distinction to be made between how they conceive of what Catholicism is and what it is in truth. Some critics would claim Catholicism is too ascetic, others too mystical or lenient, etc., Everyone has their own take on it. Are they all referring to the same Catholicism? If so, why the divergent opinions about it? Could it be due to the fact that it isn’t actually Catholicism that some or many are referring to? I mean how could contradictory opposites about Catholicism be true at the same time: ascetic and hedonistic, rigid and lax, rational and mystical, etc.?

Is an atheist actually refusing to acknowledge the real God when they scornfully depict God as the Flying Spaghetti Monster? Or are they referring to a false conception they have of God?

Are all critics referencing the same entity or are they referencing mere or misconstrued conceptions of what they think and not the reality at all.

I am not clear that merely because they say or claim they are, that that is sufficient to make the case that they are speaking of the reality about which they suppose they are. I would submit that there are some Catholics who misunderstand or misrepresent Catholicism because of their errant views about it. Is it really Catholicism that they are speaking about?

In some superficial sense, perhaps, or if nominalism happens to be true.

I would suggest that the issue is that conceptions of God are not the reality of God and that merely because some (whether they be Christian, Muslim or other religion) think they properly worship or refer to God does not mean they are. We might, in fact, be worshiping mental projections, ambitions, ideals, end goods, etc.


@FrDavid96, do Mormons worship the same God too? At what threshold of heterodoxy do we start to say that an individual no longer worships the same God, but rather a self-conceived version of (and therefore false) god.


Or should it be said that all people (Muslim, Christian, Atheist, Hindu) who love the good as best as they can but by no fault of their own (invincible ignorance) do not perceive the fullness of Catholic truth about God, insofar as they love the good which they do know, love the one true God?


I like your post. I think the good must be of God. I think that many seeking good think it is God without knowing it . Wait, I mean folks need to seek sincerely in truth. Im sure you already knew that.


You start with a premise/conclusion that both Islam and Christianity have the same God rather than trying to find out what each believes and whether their respective diety can reconcile to a same entity.

For the sake of discussion, how did you get there, because it is a possibility too that Islam’s god may be different from Christianity’s? It can be Islam’s god is x, and Christian’s God, is well, God or y, to differentiate the two. You can’t discard that possiblity, can you?

To determine whether x and y is the same or not, can we not try to scrutinize what each believes x and y to be? And then decide whether they are the same.


There is belief in one God (Monotheism) but a different understanding of that one God, as stated.

“we believe and confess one God, although in different ways, and praise and worship Him daily as the creator of all ages and the ruler of this world”.


That’s a fair summary of what Vatican II said. Except for the “or” at the beginning.

It isn’t about one-or-the-other; your post here, or your previous one.

The two statements address different issues.

I’m going to try, just a little bit more, to explain this. I might regret it. I might be just continuing to waste time, but I’ll try just a little bit more.


It’s a fair question. At what point do we draw the line?

With regard to Mormons, they do indeed also believe in the God of Abraham, the God that they call “the Father”, but their beliefs about that God are so different, so completely and utterly different, that Mormonism is a completely different religion from Christianity. That believe that the God of Abraham is just one of many others. So, they still believe in Him, but their beliefs about Him are irreconcilable to Christianity.

You’re still making the same mistake of confusing 2 different questions.

  1. What God does a religion believe?
  2. What does that religion believe about that God?

It is rather simply reasoning here. Those 2 questions are exactly that, 2 different questions.


People just do not understand the very simple reality that there are 2 different questions.

  1. What God does a religion believe?
  2. What does that religion believe about that God?

Now, if I were to say that Anglicans do not believe that Christ established one and only one Church here on earth, that Anglicans believe in a god who inspired Queen Elizabeth I to persecute and murder Catholics, and therefore the Jesus Christ worshipped by Catholics and the Jesus Christ worshipped by Anglicans are 2 different Christs, that would be absolutely absurd. Everyone would easily recognize the lack of any reasoned thought in such a claim, that the Christ of Catholicism and the Christ of Anglicanism are 2 completely different people.

It is the same with regard to Islam. People can post all day long about differences between Islam and Christianity. It’s just a waste of time. No one doubts that the 2 religions have different beliefs.

The fact (not in dispute) that Muslims believe different things about God doesn’t change the fact that their God is still the God of Abraham, the same God professed by Jews and Christians.


No. It is not about monotheism.

A person can be monotheistic without necessarily believing in the God of Abraham.

You keep trying to force the issue of “what they believe” It is not about what they believe. It is not about specific doctrines. It is about which God they believe in. 2 different questions.


That is what I was attempting to get at by distinguishing between the “office” of God (I.e., the 3 Omni characteristics of classic theism or monotheism) and the “Person” of God (I.e., the holder of that office.) Clearly, Islam is monotheistic and a fortiori Muslims are therefore monotheistic.

The question, therefore, reduces to the understanding of Islam with regard to Who God is. Clearly, Christianity as the only Trinitarian theology, holds that three eternal Persons are God. Islam disputes that. So Islam CANNOT believe in the same Person of God that Christians do. One of the two are clearly mistaken about the nature of Who God is.

You keep harping back to Abraham, presumably referring to the belief that Islam through its Arabic heritage views itself as coming from Abraham through the sonship of Ishmael, Hagar’s son. Thus, Islam sees God more as “Master” than Father and as a result views submission as primary in what is owed to God as Master. Fine. All of that could be true, while it could also be true that the concept of Who God is could have gone wildly off track in the person of Mohammed and his claims relative to the revelations he received from his night visitor. That would mean Islam could, like the neighbor in my analogy, be completely wrong about Who God is and what the holder of the office of God their belief system implies about his nature such that Islam does not really worship the same God as Christians do, but rather the God of Mohammed’s imagination. That God need not exist for Muslims to worship him, which means there need not actually be two Gods. The one God would exist, but the other would be a fictional depiction of the person holding the “office” of God.

In other words, the office would be the same in both, but claims about the nature of the character Who holds that office in Christianity and Islam could be very different, incompatibly so.


It is rather simple.

Abraham existed. He was a real person. Everyone agrees on this. Even if we don’t agree, even if someone were to claim that Abraham is just a metaphor for a certain early nomadic family or tribe, it makes no difference conversationally.

Abraham worships a certain God. That God doesn’t have a name, but eventually we will come to call Him “I am Who I am” So, to save myself some typing, I’ll just call Him “God” from now on.

Again, Abraham worships God. Abraham has 2 sons, Isaac and Ishmael.

Isaac continues to worship the same God his father worshipped. Isaac has a son. Jacob continues to worship the same God as his father Isaac and his father Abraham. This continues down through the centuries. Each generation continues to believe-in and worship the same God as the generation before.

Ishmael continues to worship the same God as his father Abraham worshipped. Ishmael does not invent a new God because he doesn’t get along with his half-brother Isaac. He continues to worship the God of his father Abraham. Ishmael’s descendants continue to worship the God of their fathers.

Now, whether or not we want to say that Ishmael is a direct blood ancestor of Mohammed is irrelevant. We do know that Ishmael’s line continued because centuries later, there is a group of people called “the Ishmaelites” who continued to believe in that same God of Abraham.

Centuries later, along comes Mohammed. Mohammed already believes in the same God as his father’s generation, and his father’s generation, down to Abraham. The God is still the same God.

Mohammed writes a book called the Koran. In this book, he says things about the God of Abraham that are inconsistent with the Jewish and Christian (spiritual descendants of the Jews) understanding of the God of Abraham. Mohammed does not invent a new God. He does not deny the God of Abraham and replace that God with another one. Instead, he says new things about the God of Abraham. Many of these new things contradict what people already know about the God of Abraham. Those contradictions do not change the basic fact that Mohammed is still speaking about the same God of Abraham. Mohammed does not invent a new God, he invents new beliefs about that same God.

The descendants of Isaac and those of Ishmael continuously worship the God of their father Abraham. At no point do they cease to believe in that God and invent another God. We know that they will say different things about that God, but saying different things about God is simply not the same thing as inventing a new God.


You keep repeating the same mistake.

Mohammed did not invent a new God. He invented new things to say about God.

The truth (or lack of it) of those things he said doe not change the fact that he was still speaking about the same God. The fact that what he said is incompatible with Christianity does not mean that he invented a new God.


This is where your logic falls apart.

Jews likewise do not believe in the Trinity.

We all know (and I hope accept) that the God of Christianity is also the God of Abraham, the God of the Jewish people.

According to your reasoning, Christians do not believe in the God of Abraham because Judaism is not Trinitarian. That position is likewise untenable.


Well, no. What the Jews understood about God they understood because of what God did or did not reveal to them about Himself. It wasn’t as if the Jews invented the God they worshiped out of whole cloth. God led them over thousands of years as documented in the Old Testament. This is quite different from the story of how Islam came to be. Islam and its conception of God could very well have been invented out of whole cloth by Mohammed because it relies more or less completely on the veracity of Mohammed’s claim quite independently of Judaism. There is nothing in the OT that supports or points towards Islam, except perhaps the passages about Hagar and Ishmael, although those pertain more to a people, the Ishmaelites or Arabs than it does to a religion or belief system.


Here’s my understanding as to why we can say Muslims acknowledge and even worship the same God as us.

First, I think there should be noted the difference between worshiping God in Spirit and in truth, offering Him “true worship,” having supernatural faith, obeying Him, etc., and acknowledging God or worshiping God according to the virtue of religion (which is not a theological virtue, but a natural virtue that falls under justice).

St. Thomas defines this virtue in the Summa as “to show reverence to one God under one aspect, namely, as the first principle of the creation and government of things.”

Can Muslims do this? They certainly worship “God” as First Principle and Supreme Governor of all things, but is it the same God we know? Can one acknowledge the one God without acknowledging the Trinity?

First, faith is required to acknowledge the Trinity. The Trinity cannot be reasoned out, as St. Thomas explains:

I answer that, It is impossible to attain to the knowledge of the Trinity by natural reason. For, as above explained (12, 4, 12), man cannot obtain the knowledge of God by natural reason except from creatures. Now creatures lead us to the knowledge of God, as effects do to their cause. Accordingly, by natural reason we can know of God that only which of necessity belongs to Him as the principle of things, and we have cited this fundamental principle in treating of God as above (Question 12, Article 12). Now, the creative power of God is common to the whole Trinity; and hence it belongs to the unity of the essence, and not to the distinction of the persons. Therefore, by natural reason we can know what belongs to the unity of the essence, but not what belongs to the distinction of the persons.

Therefore, we can know of God, as the Principle of all things, apart from faith, but we can only know of the Trinity with faith since it is a revealed dogma. The First Vatican Council also defined that God can be known from natural reason alone (Dei Filius, Canon 2.1) and St. Paul says, on account of this, those who do not acknowledge God (but worship idols, are atheists, etc.) are without excuse (Rom. 1:20).

Therefore, one can acknowledge the one God and Creator of all things without having faith and acknowledging the Trinity. But do Muslims do this?

How can we say whether or not we are talking about the same thing? It is the essence of the thing that determines what it is. If we acknowledge the same essence, we acknowledge the same thing. What we can say about the essence of God is that it is the same as His existence. This is summed up as “God is” or, in His own words, “I AM” or “I AM who AM.” (Exo. 3:14).

to be continued…

Worshipping the Wrong God

continued from above

This concept is formally referred to as the “aesity” of God. Essentially, aesity means self-existence. Aesity explains the metaphysical nature of God as a purely self-existent being that exists in complete actuality. God is not a being that is created by another god; neither does God create Himself into existence. Rather, God has always existed as an unchanging, completely actualized being. God has his Being of himself and to himself such that he is absolute being and the very definition of existence (see Acts 17:22-28). Since God’s existence is the same as his essence, it follows that God is existence. (Note: this is not to assert pantheism. All other beings participate in his existence on a contingency and thus do not possess the essence of God. Therefore, no other being can be said to be a god or share a part in the godhead since they exist solely on a contingency.) This concept is at the root of the definition of all of God’s other perfections because if God is absolute being he must logically contain in Himself all perfections of being.

Since God’s essence is existence, if one acknowledges His essence, one can only acknowledge He who exists–it is impossible to acknowledge a completely actualized being that is not the one and only God. Similarly, there cannot exist two of such beings, because then neither would contain in Himself all perfections of being.

The CE article on Essence and Existence explains this:

Catholic Encyclopedia:

-If essence and existence were but one thing, we should be unable to conceive the one without conceiving the other. But we are as a fact able to conceive of essence by itself.
-If there be no real distinction between the two, then the essence is identical with the existence. But in God alone are these identical.

Since Muslims do conceive of God as being completely self-actualized, of being non-contingent, as having aesity (see this Muslim article, ), then they therefore can only be said to acknowledge the one God who exists and it is to Him that they honor and worship as First Principle and Creator according to the virtue of religion.

I would say therefore that we know God; they know of God. This is the difference between affective and speculative knowledge. St. Thomas makes this distinction in his commentary on John to reconcile Biblical passages where Jesus says one must know Him to know the Father with those where people without faith are said to know or worship God (such as those passages cited above from Acts and Romans). We worship God in Spirit and in Truth and serve Him in supernatural faith and charity, they acknowledge and worship only in a natural way.

This of course does not mean what they claim as His revelation actually is or that their religion dates back farther than it actually does, or that they are justified in everything they do, etc. Whether people do good or horrible things in His name does not change or determine who God is.


Thank you for the trouble. A good explanation of the Church’s position which I couldn’t add anything further to. Perhaps I can use some of that in trying to explain this issue myself.

For a searching mind though, the Church coming out with this stance seems to be trying to be politically correct and this is certainly not the first time she is so. It is on this basis that it can be quite a controversy for many Catholics.

In other word, like I earlier said, this argument is based on pre-determined premises, some are matter of factually while others are just simply assumed.

Example of the latter is that descendants of Abraham would still worship his God. Of course we know this is untrue; even within the OT, the chosen people sometimes didn’t themselves. Thus if Muhammad can modify this understanding (of God) and the worship, a possibility that now they may worship an entirely different god remains a possibility. Saying that they are monothiestic simply means that they worship only one diety.

As for the Jews, it is wrong analogy to equate them with the Muslims that since they too do not believe in the Trinity and so not necessarily worship different God. Christians derived their knowledge of God from the Jews (Judaism) and if that was true then, therefore it is now. The OT has not changed. The Quran is not OT though, in fact nothing remotely close.


The long answer to this short question is



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