Jim West stumbled across this little tome: De Diepten des Satans, of Geheymenissen der Atheisterij (“The Depths of Satan, Or, The Secrets of Atheism”) by the Dutch writer Frans Kuyper in 1677. Fun stuff, if you read Old Dutch.
Google Translate can’t handle old Dutch – it’s too different from modern Dutch, which why the New Netherland Project stays in business – but there seems to be something in the extended title about the “demons currently named Cartesians and Quakers.” Looks delightfully insane.
My guess is that this is part of the 17th century’s wave of anti-atheist publications. The first that I know of is Henry More’s 1651 An Antidote Against Atheism (available via Wikisource), although he apologizes for writing the book because there are “so many already on the same Subject.” Obviously, there are earlier works that I’m not aware of.
Also of note is The Wisdom of God Manifested in the Works of the Creation by the naturalist John Ray in 1697. (Google copy is a much later edition.) This is one of the earliest and most through presentations of the argument from design. For this sin Ray was ruthlessly plagiarized by his followers, including William Paley.
The best guess is that this is all a result of the Protestant Reformation. Faith had stopped being a matter of trusting in God and become a matter of believing the right things about God. The idea of believing in God carried with it the idea of not believing in God, and the notion of a loss of faith terrified people. Some people who were perfectly innocent of atheism, such as Spinoza, were branded as atheists and harshly treated. Kuyper here was a particular critic of Spinoza, and I have a hunch that he’s the real target in this work.
Like current apologetics, these works were meant to reassure the faithful rather than convince the atheist. The demons that Kuyper was afraid of were most likely the demons of doubt in his own head.