When?

SEE if you can put an approximate date on the following paragraph from a book I am reading.

"A great deal of nonsense has been written about missionaries. When they have not been described as the servants of imperialists or commercial exploiters, they have been regarded as sexually abnormal types who are trying to convert a simple happy pagan people to a European religion and stunt them with European repressions. It seems to be forgotten that Christianity is an Eastern religion to which Western pagans have been quite successfully converted. Missionaries are not even given credit for logic, for if one believes in Christianity at all, one must believe in its universal validity. A Christian cannot believe in one God for Europe and another God for Africa: the importance of Semitic religion was that it did not recognize one God for the East and another for the West. The new paganism of the West, which prides itself on being scientific, is often peculiarly neurotic. Only a neurosis explains its sentimental lack of consistency, the acceptance of the historic duty of the Mohammedan to spread his faith by the sword and the failure to accept the duty of a Christian to spread his faith by teaching."

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To me it comes across as very modern, but is from Graham Greene's 1936 book Journey Without Maps.
I guess there are three clues that the writing is not modern:
a) using 'Mohammedan' rather than 'Muslim',
b) using 'recognize' rather than the modern UK English 'recognise',
c) defending Christianity rather than attacking it.