Ancient roots of Calvinism

Teachings from a Neo-platonic philosopher, apparently influenced by a spirit guide, influenced Augustine who influenced Calvin & modern theology. Thus, teachings and doctrines of devils may have ultimately influenced ideas of Calvin and modern theology (including Calvinism).

The trace-back is 

modern theology - Calvin / Augustine - Neoplatonism - Plotinus - devil?

Historically, Calvin claimed he could have written most of his teachings by quoting Augustine. 

Augustine was influenced by Neo-Platonic philosophy. The major figure of Neo-Platonism is Plotinus, who is "generally regarded as the founder of Neoplatonism." 1

Porphry, who knew Plotinus, reported that an Egyptian priest of Isis claimed, on meeting with Plotinus, that  Plotinus had a spirit guide who was a god. .. or, a devil? 2

HOMAGE TO PLOTINOS FROM A VISITING EGYPTIAN PRIEST.

Plotinos showed a natural superiority to other men. An Egyptian priest, visiting Rome, was introduced to him by a mutual friend. Having decided to show some samples of his mystic attainments, he begged Plotinos to come and witness the apparition of a familiar spirit who obeyed him on being evoked. The evocation was to occur in a chapel of Isis, as the Egyptian claimed that he had not been able to discover any other place pure enough in Rome. He therefore evoked Plotinos's guardian spirit. But instead of the spirit appeared a divinity of an order superior to that of guardians, which event led the Egyptian to say to Plotinos, "You are indeed fortunate, O Plotinos, that your guardian spirit is a divinity, instead of a being of a lower order." ...

PLOTINOS'S ATTITUDE TOWARDS THE PUBLIC MYSTERIES.

As Plotinos's guardian spirit was a divinity, Plotinos kept the eyes of his own spirit directed on that divine guardian. That was the motive of his writing his book 3 that bears the title "Of the Guardian Allotted to Us." ...

Even if merely thought to be not of a devil, and really human in origin, we might think twice before blindly accepting those ideas Plotinus taught. Why were those ideas considered by his student to be those of some spiritual entity? Was Plotinus hallucinating? Do we want to build important concepts on such a foundation?

1 Timothy 4:1
Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;

We can trace influence as Calvin <- Augustine <- Plotinus <- devil?

If one discounts the existence of spirits, one might question any doctrines arising from one supposedly guided by such. On the other hand, if one does admit the existence of spirits, one might find even more reason for concern before blindly accepting the tenets of Calvinism. The Bible warns not to believe every spirit (1 John 4:1), and warns of doctrines of devils (1 Timothy 4:1). Either way, the theological concepts of Calvin that are rooted in the ideas of Plotinus become significantly questionable.

• 1See https://plato.stanford.edu/entries/plotinus/
• 2See https://www.gutenberg.org/files/42930/42930-h/42930-h.htm#FNanchor_6
• 3See https://www.gutenberg.org/files/42930/42930-h/42930-h.htm#FNanchor_6