There are a plethora of works on the history of geometry, both comprehensive and focused on individual periods. There are also plenty of course books in the history of philosophy, and no fewer course books and monographic works on the history of the Christian dogma. The author is keen to see what you can find out studying works of both the types, something that has never been tackled straightforwardly in any of them. Making no claim on completeness, the book succeeds in paving the way and grasping a handful of ideas that are hidden from the view while the reader examines one side of this conjunction.