Islam starts precisely from the idea that the infinitely transcendent God is at the same time infinitely close, – “closer than your jugular artery”, – so that he surrounds us and penetrates us, in the religious experience, like a kind of luminous ether, if it is allowed to use such an imaginative expression; the only necessary intermediary is our own attitude, el-islâm, whose central element is prayer in all its forms. The Jewish God was “distant”, but he lived among his people and sometimes spoke to them; the Christian God – the God-Man – is the “intermediary” between this distant God and man, this God who is now silent and merciful; and as for the God of Islam, he is “close” (El-Qarîb) without being “human”. There are no different Gods, of course; it is only a question of different perspectives, and “divine attitudes” that correspond to them respectively. God is always and everywhere God, and that is why each of these attitudes is found in its own way within the other two; there is always, in some way, “distance” and “proximity”, as there is always an “intermediate” element.
Christentum – Islam: Ausblicke auf eine esoterisch Ökumene (e-Book)
In this work, Frithjof Schuon compares Christianity and Islam and also looks at confessions within these world religions: Protestantism, Orthodoxy, and Shiism.