Paul, evidently knew high places are associated with devils.
2Ch 11:15 And he ordained him priests for the high places, and for the devils, and for the calves which he had made.
Why didn't they say men or flesh instead of devils?
Lev 17:7 And they shall no more offer their sacrifices unto devils, after whom they have gone a whoring. This shall be a statute for ever unto them throughout their generations.
Deu 32:17 They sacrificed unto devils, not to God; to gods whom they knew not, to new gods that came newly up, whom your fathers feared not.
Psa 106:37 Yea, they sacrificed their sons and their daughters unto devils,
We know they were not sacrificing to men because never once are any specific men noted.
There is no other book like the Bible in the world where you have to know the Author to understand the book. If Christianity were the religion of the Book then it would be no different than any other religion in the world. But, Christianity is Christ! It is the dynamic, personal Spirit of God functioning in man.