Nietzsche said “Christianity is Platonism for the people”. He believed that Christianity had inherited the Platonic trait of privileging the Ideal over the real, to be against life itself. I think the connection between ancient thought and what can be loosely termed the history of modern societies is there, it is interesting to note that the Vatican owns some of the many pre-Socratic Greek fragments and the thought behind the interpretation (eisegesis) of the bible was heavily influence by the knowledge of the ancient Greeks. This is why there were power struggles over meaning (Copernicus, ect) and the Church held great power in part because of the ownership over the meaning of the ancient texts. ‘Reason’ allowed the likes of Copernicus to challenge this ‘meaning’, and eventually, new paradigms were set. Incidentally, for much of the last two thousand years ‘Reason’ was not necessarily a secular task only, Kant, as far as I know, was a committed believer in god, his attacks on specific arguments for God’s existence, were to “elucidate the sources of the dialectical errors, which he will expose in relation to the specific arguments for God’s existence”, clearing the ground for a better understanding of god.
Back to Nietzsche again, from Beyond Good and Evil: “What astonishes one about the religiosity of the ancient Greeks is the tremendous amount of gratitude that emanates from it – the kind of man who stands thus before nature and before life is a very noble one! – Later, when the rabble came to predominate in Greece [he means Plato and his school], fear also overran religion; and Christianity was preparing itself.”
History connects us all; there is no possibility of tabula rasa now, not even in pre-Socratic times, they were influenced by the East and Egypt in particular.