This is both extremely reductive and also totally false. Obviously religions influence other religions, but all your examples don't hold up to scrutiny. Islam

This is both extremely reductive and also totally false. Obviously religions influence other religions, but all your examples don't hold up to scrutiny. Islam is just Judaism? What? Christmas isn't pagan. That's a myth. Modern Christmas was invented by German Protestants and then spread to England where it was given a huge shot in the arm by Charles Dickens. You're wrong about Zen Buddhism. Syncretism exists, but Herbert is just so lazy. He mashes together two different religions with very little in common other than Orientalism (his greatest vice as a creator).