A new friend of mine recently passed on that previous quote on Islam by Churchill. And now he passed this gem by Chesterton on Islam:
There is in Islam a paradox which is perhaps a permanent menace. The great creed born in the desert creates a kind of ecstasy out of the very emptiness of its own land, and even, one may say, out of the emptiness of its own theology. [...]
A void is made in the heart of Islam which has to be filled up again and again by a mere repetition of the revolution that founded it. There are no sacraments ; the only thing that can happen is a sort of apocalypse, as unique as the end of the world ; so the apocalypse can only be repeated and the world end again and again. There are no priests ; and yet this equality can only breed a multitude of lawless prophets almost as numerous as priests. The very dogma that there is only one Mahomet produces an endless procession of Mahomets.