The Two Big Monotheisms – This ‘Minor’ Difference Will Shock You!

Islam and Christianity are both sometimes referred to as Abrahamic religions.

There are important similarities, of course. Monotheism, some [limited, and largely superficial] similarity in Scriptures, prophets, an afterlife, concern for the poor, and other precepts. Similarly backwards and superstitious, according to the new atheists of internet fame.

There was a fair amount of controversy in Christian circles a while ago over whether Muslims and Christians worship the same God. In the debate there was a tendency, as I read it, for philosophers to give a nuanced ‘yes’ response, and evangelical theologians to usually give a quite strong ‘no’. Generally the two seemed to be talking past each other.  My own take is that Muslims and Christians and other theists in general do recognise the same creator God. I take this to be the teaching of Psalm 19, and Romans 1, for instance. Similarly, all humans have shared access to a moral intuition, as seen in Romans 2. These twin shared pillars in our understanding of the world can be a basis for respectful discussion, I believe.

But, different religions don’t worship the same God, because different religions pack in many other attributes regarding what they worship.

Let’s say I have a next-door-neighbour, Bob. Bob is recognised as an interesting figure in the neighbourhood, and everyone knows his address, next to me. But other details are disagreed upon. Some say he’s a retired musician, others that he’s a spy for the Russian government, others that he works from home as a programmer. If Bob has come and chatted with Zoe and given her evidence of who he is and what he’s like, Zoe is in a privileged position regarding who Bob is. The others, including me, still know Bob exists, but are mistaken about who he really is. Perhaps one day we all find reason to praise Bob in the local newspaper, referring to our own conflicting beliefs about Bob’s awesome history. I take it that we are all in a sense referencing the same Bob [as picked out by a character such as ‘Zach’s next door neighbour’, but not praising the same Bob. I think this is analogous to the situation world religions are in regarding God. The challenge is, as Jesus puts it, to worship God in spirit and in truth – i.e. to worship the God revealed by God’s spirit, and worship God for who God really, truly, is. But, this was an aside – on to the substance!

There’s much more to say of course. Two diverse divergences that I am interested in and may write about later are different stories concerning Abraham (in the Old Testament, Abraham and Isaac point towards salvation through faith in a final completed substitutionary sacrifice, while in Islamic teaching, Abraham and Ishmael are used, it seems, to point towards merit earned by works) and different dominant concepts of natural law.

But, for now, a difference that may seem quite minor that I stumbled across today: In Islamic law, adoption, in the full sense we are familiar with in the West, is not permissible. In Christianity, adoption, in the full sense, gets to the very heart of the gospel.


In Islam, the care of orphans is encouraged, and the care of other children not one’s own is permitted, but full adoption is not permitted. I have kept to what I believe to be orthodox Sunni Islamic sources online in briefly preparing this – I welcome any corrections.

According to the Islamic faith:
Inheritance to adopted children is limited under divine law (to a maximum of 1/3 of the total inheritance):
“Those related by blood are more entitled to (inherit from) each other in the Book of Allah.” (Qur’an: 8:75)

Taking of the adoptive father’s name is forbidden:
“Nor has He (Allâh) made your adopted sons your sons. Such is (only) your (manner of) speech by your mouths. But God tells the truth, and He shows the way. Call them by (the names of) their fathers, that is better in the sight of God”. (Qur’an 33:5)

One of the main reasons for this ruling seems to have been laws around marriage by the adoptive father to an adopted son’s wife, that became part of the Qur’an thanks to a situation involving Muhammed and the wife of an adopted son of his. (Qur’an 33:37). My focus here is not on Muhammed however, so investigate this if you wish.

The accepted wisdom also seems to be that ‘adopted’ children in Muslim families should be asked to leave or somehow separated out from the rest of the family at the age of puberty, but this is a bit less clear than the rules on names and inheritance.


According to the Christian faith:
God has adopted people who trust in Jesus, by something like a legal decree (interestingly, this language of a legal decree is exactly what I saw decried regarding ‘Western’ adoption in Islamic sources). We are made full children of God, with full inheritance, and God’s full love.

 “The Spirit you received does not make you slaves, so that you live in fear again; rather, the Spirit you received brought about your adoption to sonship. And by him we cry, “Abba, Father.”” (Romans 8:15)

In love he predestined us for adoption to sonship through Jesus Christ, in accordance with his pleasure and will— to the praise of his glorious grace, which he has freely given us in the One he loves. (Ephesians 1:5)

Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God— children born not of natural descent, nor of human decision or a husband’s will, but born of God. (John 1:12)

As summarised by JI Packer, “Our understanding of Christianity cannot be better than our grasp of adoption… If you want to judge how well a person understands Christianity, find out how much he makes of the thought of being God’s child, and having God as his Father. If this is not the thought that prompts and controls his worship and prayers and whole outlook on life, it means that he does not understand Christianity very well at all.”  (in Knowing God)

A short video from JI Packer:

Of course, adoption is a difficult and sensitive issue, not without sensitivity on my part too, but I find the essential truth of having been adopted as a child of God as a fellow heir with Jesus to be a remarkable encouragement.