According to Islam, Allah is unknowable. He is so transendent, so exalted, that no man can ever personally know Allah. To the Muslim the idea that Allah is a person or a spirit is blasphemous because this would demean the exalted one. Allah is not limited by anything. He is not even limited by his own nature. Swamiji used to react to this belief by saying: "For the Mohammedans,it is impossible to have this idea of God as a child; they will shrink from it with a kind of horror. But the Christian and the Hindu can realise it easily because they have the Baby Jesus and the Baby Krishna. (III:96)
Swamiji also reacted on the 'universal brotherhood' in Islam by saying: Mohammedans talk of universal brotherhood, but what comes out of that in reality? Why anybody who is not a Mohammedan will not be admitted into the brotherhood; he will more likely have his throat cut. (II:380)
More from Swamiji on this aspect: "Now, some Mohammedans are the crudest in this respect, and the most sectarian. Their watchword is "There is one God, and Mohammed is His Prophet". Everything beyond that not only is bad, but must be destroyed forthwith; at a moment's notice. every man or woman, who does not exactly believe in that, must be killed; everything that does not belong to this worship must be immediately broken; every book that teaches anything else must be burnt. From the Pacific to the Atlantic, for five hundred years, blood ran all over the world. That is Mohammedanism! Neverthe- less,