Darwin and the ship Beagle, as well as every other ship entering the Pacific ocean had to sail through the treacherous waters of the Land of Fire at the tip of South America. Many ships didn't make it, and shipwrecked.
I heard (or must have read) the response Darwin wrote to the London newspaper editors who were mocking and dissing the Christian missionary movement of England. He noted that if it weren't for the work of the missionaries, the native cannibals would have eaten all the shipwrecked sailors at Tierra del Fuego! He expressed gratitude for the work of the missionaries that made that sailing, and his research much safer.
Does anyone have evidence for this event by Darwin? (Not that he was an advocate of religion personally.)