After a quick read, I'd say Arinze's manner of speaking relies excessively on the assumption that he audience shares his views and semantic conventions. To everyone else (including Catholics not trained in the idiom of his particular mission) he comes across as ambiguous or worse. Arninze needs to understand that not everyone can hear what he's saying unless he uses terms common to all.
What did Mother Teresa say?
We are to help Buddhists be good Buddhists, to help Jews be good Jews, to help Muslims be good Muslims.