I have always loved science: when most boys said they wanted to be policemen, I wanted to be a paleontologist and study dinosaurs. Now as a priest, I still enjoy looking at science as a sign of God’s beautiful work in the world. Looking for an Islamic understanding of natural science, I came across a few lines from Al-Ghazali, possibly the most influential Muslim after Mohammed:
“Natural sciences, some of which go against sharee’ah, Islam and truth, so it is ignorance, not knowledge that may be mentioned alongside the other branches of knowledge… there is no need for the study of nature.”
These divergent views on science illustrate one difference in how Muslims and Christians view God. We worship the same God but that doesn’t mean we understand him the same way. Obviously, Muslims and Jews believe in a monotheistic but not a Trinitarian God. Since God is the source of all meaning, how we understand God affects how we understand everything. Recent news stories have compared the two faiths with regard to terrorism, Syrian refugees, and obeying American laws, so I think it appropriate to explain the fundamental difference in how the two religions understand God. I will mention a few practical consequences at the end but I will focus on differences in how we understand God. The three primary differences I see are the relationship between God’s intellect and will, God as Father or master, and God as monad or Trinity.
(Notes:  Throughout this essay I will use the word “Allah” not to intend he is a different God but to indicate ways in which Muslims misunderstand the one true God. Writing “God according to Muslims” repetitively made for a tedious read.  I am using the theoretical, philosophical and theological, understanding: individual Christians and Muslims often vary.)
Will and Intellect
In Islam, Allah’s will is above his intellect, while in Christianity, God’s intellect is above his will. This difference in the internal hierarchy might seem like an abstract distinction but as we work through the consequences, we realize that this tiny change makes a huge difference. God can will things beyond our reason but not against it while Allah can will things against reason. This distinction of superiority is the reason for the discrepancy regarding science – if God wills arbitrarily, why try to understand non-existent laws. The same applies for finding beauty in God’s handiwork of creation. The same distinction applies to morality: there is a rational reason Christians believe in one-man-one-woman marriage but the reason a Muslim can have four wives but not five is Allah says so. With regard to wives, one is a special number while four is simply an arbitrary limit chosen. As Christians, we understand that God always wills good, yet permits evil, but Allah can will that someone does evil.
As Christians we can ask why God does or permits certain acts: why does God allow evil? St Augustine answers that evil is never willed because it is not something but a lack and God allows evil so a greater good can come about in mysterious ways. Why did Jesus have to undergo the cross? St Anselm says that our sin caused an infinite offense because is an offense against God but only God could make an infinite reparation but man must make reparation for the offense, thus the God-man’s suffering is the proper reparation.
Muslims can’t ask questions the same way: why does every Muslim need to perform the Hajj (pilgrimage to Mecca)? Because Allah willed it. Some slight explanations might be given but nothing approaching the Christian respect for reason. Why did Mohammed marry Aisha at six or seven, and consummate the marriage when she was nine? Because Allah willed it, period. No further explanation can be given.
The basic distinction: our Trinitarian God does everything according to reason while Allah can follow reason or do things arbitrarily.
Father and Lord
In Christianity we call God “Father”; Islam has 99 names for God but none are familial. Scott Hahn tells a story: before debating with an Imam, the two of them were talking. At one point, Hahn called God, “Our Father,” and the Iman got enraged yelling that Dr Hahn spoke blasphemy. Hahn was a little puzzled as we pointed out that among the 99 names there are “The Loving,” “The Nourisher,” “The All-Aware,” and “The Indulgent.” He asked why if you’re going to give God names corresponding to all the traits of a good Father why you can’t call him a Father? The Iman replied with a story: he had a dog will be loved, who he nourished, who he indulged, but he was moving and in his new apartment pets weren’t allowed, so he was putting his dog to sleep.
While “Christianity” is named after the central person of Christianity, Jesus Christ, “Islam” means submission. Submission is viewed in a fairly harsh sense – not a filial submission to a good Father but a slave’s submission to an arbitrary master. When God asks us something difficult, he asks as a gentle Father who we know wants the best for us. When Allah asks something difficult, a Muslim may or may not be given a reason – he is asked to submit like a slave.
An obvious sign of the daddy or master distinction is the difference in how the two religions view heaven. Since God is Father, the best we can imagine is being united with him in heaven: a family scene or a giant festive banquet of all Christians united together. Since Allah is simply a master, he instead motivates with a sensual vision: drinking wine on a couch with 70 virgins caring for you. Everyone wants to be with a good Father, but not everyone wants to be with a master.
The view of God as Father or master is partially a consequence of the previous point. If the intellect is first, infinite and perfect, God will always will what is good for each of his creatures – thus, it is appropriate to call him “good Father.” If, on the other hand, Allah is somewhat arbitrary in what he chooses for his creatures, treating them as peons, it is only appropriate to call him “Master.”
Monad and Trinity
We all remember from catechesis that there are three persons in one God: each of the three is God but each is not the others. Cardinal Ratzinger stated: “God is One and Three: he is not an eternal solitude; rather, he is an eternal love that is based on the reciprocity of the Persons, a love that is the first cause, the origin, and the foundation of all being and of every form of life. Unity engendered by love, trinitarian unity, is a unity infinitely more profound than the unity of a building stone, indivisible as that may be from a material perspective. This supreme unity is not rigidly static; it is love.” Love unites the Trinity and brings it closer than an individual alone.
On the other hand, in Islam God is a “monad” as he is absolutely one, singular and unique. There are no relations or modes in God. He simply is above everything else, alone in majesty.
If God is love – not only love but subsisting and uniting love – he has perfect happiness in himself and if he decides to create, his act of creation will be driven by love. Even though Allah is “The Loving,” love is simply an attribute of his relationship to believers and not part of his nature. God hates none of his creatures although he may hate some of their acts (sins); while Allah, according to IslamQA, “Hates those who disbelieve and disobey Him… [and] may hate a person at one time and love him at another time, according to his actions.”
The fact that God is Trinity makes God personal and relational. Allah is a personal God but Muslims are called to a much more formal and fear-based relationship. The Trinitarian nature of God puts love at the center of his nature rather than simply an external attribute. We are called to have the Trinity well within us while Allah is so transcendent, he always dwells apart. Even the Kaaba, the central rock in Mecca, is not a point of God’s presence on earth but simply where they believe God ordered Abraham and subsequent prophets to pray.
The Trinity implies relationship and love while a monad simply exists above and beyond all else.
Many practical consequences come about but I’ll stick to three: law, terrorism, and persecution.
Muslims generally want Sharia law and Christians generally want Biblical law. However, there is a huge difference. Since we as Christians believe in a rational, fatherly, and loving God we see the Bible as giving principles but letting our human reason decipher later laws from these principles. For example: the constitutions of Canada and the USA are different but they’re both based upon the Bible; the Bible forbids adultery but we realize that enforce that as a law would cause more problems than it would resolve; and we can create corporate legal persons (non-existent in Sharia), essential for modern economies, even though these came about later. On the other hand, since Allah is an arbitrary transcendent slave-driver, when he revealed Sharia law to Mohammed, it was perfect and cannot be improved or modified. Thus, the law that four male witnesses are needed to prove rape or adultery unless a person admits to it, cannot be improved. A practical consequence of this law is that if a woman accuses a man of rape but can’t find four males witnesses, she is punished for admitting adultery: it’s estimated that 80 percent of women in Pakistani jails are there as rape victims with insufficient witnesses. Biblical law starts with basic principles and then reasons to their particular application in the society while Sharia law begins and ends with a perfect legal system developed in the time of Mohammed.
Terrorism is radically different in Christianity and Islam. There have been Christian terrorists such as the IRA but they were terrorists for political reasons and despite being Christians. We believe in absolute morality where means never justify the ends – a Christian couldn’t kill baby Hitler even with foreknowledge because killing innocents is never permitted. However, since Allah is arbitrary and can will what would otherwise be evil, means justify ends. Thus, if suicide bombings expand Islam, they can be what Allah wills. That might sound crazy but according to Pew research, 13 percent of American Muslims, 24 percent of British Muslims, and 35 percent of French Muslims said suicide bombings are justifiable. Muslims often disagree on what Allah wills but a significant proportion believe he can will the evil of suicide bombings. If Allah treats you as a slave and arbitrarily wills what you should do, terrorism is an option, but since God always wills the moral good, terrorism is always an abomination.
Faced with denying their faith in persecution, Islam and Christianity take opposite paths. Christianity hails the martyr, “witness,” as the supreme example of what it means to be a Christian and follow Jesus. Muslims, on the other hand, maintain a doctrine of Taqiyya, which allows a Muslim to hide his faith in order to prevent consequences of being a Muslim such as death or loss of property. In Traitor, a 2008 film about an agent inside an Islamic terror group, the terrorists drink wine, forbidden in Islam, at a French café to hide they are Muslims. Taqiyya makes trusting Isalmic apologists in the West difficult because we can never be sure if his responses are authentic or Taqiyya: an apologist would be justified in claiming Islam was against all terrorism, even if believed otherwise, in order to protect himself and other Muslims from danger.
Since God is the source of all meaning, our view of God changes how we view all reality. Some minor changes in the differences between how Christians and Muslims view God makes radical changes in the way we each practice our faith. Always remember that God is your rational Father united in the Trinity by love.