Indeed. But the funny thing is that we are all made to believe that Christianity "absorbed" some pagan symbols and rituals in order to make way in the northern part of Europe back then.
As I see it, it is actually the other way around, wherein Christianity did not absorbed it but was actually based upon the very same things.
Your "as above so below" indicates hermetics. Indeed there are a number of vehicles known to have carried knowledge through the ages.
I really like your indication of the one key or level. There are many.