I am looking for a word to describe a religion which is flexible or liberal enough to accept a variety of folk beliefs, magical practices, other demons etc. The author (translator) of the text which I am editing used “absorbent religion” (the text was translated from Polish), but I am quite sure there is a much better word, which seems almost on the tip of my tongue, nevertheless I am unable to conjure it up. Some help would be much appreciated. PS.This is an academic paper about an ancient religion.
If the adaptation represents a substantial, rather than formal or stylistic change, then the word you are looking for is synchretic.
If the adaptation is merely a change of form dictated by the language and culture of a particular group, but the belief system is not changed in any fundamental way, then one could speak of acculturation.
Your author, however, may have intentionally avoided this terminology and opted for something more neutral, which you could translate as, say, flexible.